The word "imitation" is related to words like "mime" and "mimetic," both of which have base meanings of copy. To "imitate" something is to make a copy of that thing. We use the word "imitation" as an adjective to describe something that is a copy (or as some will say, quite negatively, a "knock-off".) At the store, we can buy "imitation vanilla," which is a kind of copy of vanilla used for cooking. A "simulation" is a copy of something else—think of related words like "similar" and "similitude." Therefore, something that is "simulated" is "imitated."

“Far-fetched” is an adjective that means implausible, so we need to pick out an answer choice that means something like unlikely. That means that “expected” cannot be the correct answer, because “expected” means thought of as likely to occur, making it an antonym, not a synonym, of “far-fetched.” “Improbable,” however, is an adjective that means either not likely to occur or be true, and because “improbable” is the answer choice closest in meaning to “far-fetched,” “improbable” is the correct answer.

"Irrefutable" is an adjective meaning "impossible to deny or disprove." While "undeniable" and "implausible" may each look like a potentially correct answer because like "irrefutable," "undeniable" and" implausible" each begin with a negative prefix; however, "implausible" means "not seeming reasonable or probable; failing to convince," so it is actually an antonym of "irrefutable," and not the correct answer. "Undeniable," however, means "unable to be denied or disputed." Since "undeniable" is the answer choice closest in meaning to "irrefutable," so "undeniable" is the correct answer.

"Demonstrative" is an adjective that can mean openly demonstrating feelings or providing conclusive proof. We need to pick out an adjective that means something like showing feelings or providing proof. "Inconclusive" cannot be the correct answer because it is an antonym of the second meaning of "demonstrative," providing conclusive proof. "Indisputable," however, is an adjective that means unable to be disputed and because it is the answer choice closest in meaning to "demonstrative," "indisputable" is the correct answer.

"Unwitting" is an adjective that means either "not aware of the full facts" when referring to a person, or "not done on purpose; unintentional." So, we need to pick out an adjective that means something like "not aware of the full facts" or "unintentional." "Purposeful" cannot be the correct answer, then, because "purposeful" is an antonym of "unwitting," not a synonym. "Inadvertent," however, is an adjective that means "not resulting from or achieved through deliberate planning," and because it is the answer choir that is closest in meaning to "unwitting," "inadvertent" is the correct answer.

When something is “legitimate” it is in accord with the laws that would pertain to that class of things. For example, one could speak of a “legitimate action” as being one that is legal. Also, in a more extended sense, it can indicate conformity to the general laws of rationality or that a given thing is rightfully done in a given circumstance. For instance, a “legitimate critique,” is one that is valid given the data of the original argument. Such a critique justly finds something wrong with the argument and is therefore called “valid” or “legitimate.”

The word “specious” comes from the Latin for “appearance” or “beautiful.” When something is “specious,” it appears to be correct but really is not. It is merely apparent. Therefore, it misleads the person who considers it. Often, one will speak of “specious reasoning,” describing thereby some argument that appears to be plausible when in fact it is really false.

"Marginal" is an adjective that can besides meaning "of, relating to, or situated at the edge or margin of something," can also mean " of secondary or minor importance; not central." So, we need to pick out an adjective that means something like "of minor importance." Neither "crucial" nor "monumental" can be the correct answer, then, because each word is an antonym of "marginal," not a synonym. "Negligible," however, is an adjective that means "so small or unimportant as to be not worth considering; insignificant," and because it is the answer choir that is closest in meaning to "marginal," "negligible" is the correct answer.

"Innocuous" is an adjective meaning innocent and harmless. For example: "The innocuous bull snake is often mistaken for the deadly rattlesnake."

"Invariably" is an adverb meaning always.

"Conglomerate" is a noun meaning distinct items that can be put together make a whole with distinct parts. A space station might be an example of a conglomerate.

"Vaccine" is a noun meaning a substance that makes the antibodies which inoculates a person against disease.

"Indicate" is a verb which means to point out or to show.

"Harmless" is an adjective which means innocent and inoffensive. Harmless has the most similar meaning to "innocuous."

When someone is "infuriated", he or she is extremely angry. The word "irate" comes from the Latin root meaning anger. It is related to the word "ire" (anger) and "irritated." Although its Latin roots mean merely "anger," in English, the word "irate" means greatly angered. Therefore, it is a better option than merely saying "angry."