Conspicuous means easily noticeable, or "prominent."

"Contrary" is defined as opposite in nature. "Contradictory" is defined as asserting the opposite. Therefore, the two words are synonyms. 

"Contrary" means opposite of, so "opposite" is the synonym. 

"Compatible" means well-matched; two things that are compatible go well together. So, "well-matched" is the correct answer.

The word "congruent" means agreeable or compatible. The best choice is "compatible" because it shares the same definition as "congruent." Considering the other choices, "paired" means put together in a pair, "hardworking" means dedicated, and "denied" means rejected.

"Obtuse" is an adjective that means lacking mental acuity. Someone who is "unintelligent" is not very bright, and hence lacks mental acuity. Therefore, unintelligent is the correct answer. The other answer choices, "obtrusive," "rude," and "angry" do not mean this: "obtrusive" means conspicuous or getting in the way; "rude" means impolite or crass; and "angry" means irate or mad.

"Exhilarating" is an adjective that means "making one feel very happy, animated or elated." Tedious is an antonym, it has the opposite meaning, which is boring. Illuminating and interesting both sound similar to exhilarating, but they refer to growing lighter and gaining or seeking information. And when one is happy, animated or elated, one is not usually numb, but feels everything. So "thrilling" is the best answer, as it refers to happiness and excitement. 

"Inveterate" is an adjective that means either "having a particular habit, activity, or interest that is long-established and unlikely to change," or when describing such a feeling or habit, "long-established and unlikely to change." So, we need to pick out an answer choice that means something like "unlikely to change." "Incurable," an adjective that when used of a person or behavior can mean "unable to be changed," is the answer choice closest in meaning to "inveterate," so "incurable" is the correct answer.

“Contaminated” means infected with something. To provide further help, “prohibited” and "forbidden" are synonyms and both mean banned; “forced” means made to do something; “measured,” in the context of this question, means deliberate and careful.

"Conventional" is an adjective meaning "used and accepted by most people: usual or traditional," "of a kind that has been around for a long time and is considered to be usual or typical," or "common and ordinary: not unusual." So, we need to pick out an adjective that means something like "usual" or "ordinary." "Novel" and "unusual" are antonyms of "conventional," so neither can be the correct answer, but "standard," when used as an adjective, means "used or accepted as normal or average." Because "standard" is the answer choice closest in meaning to "conventional," "standard" is the correct answer.