"Monumental" means very large or very important, so "significant" is the answer choice closest in meaning to "monumental." As for the other answer choices, "atrocious" means terrible and evil, "petrified" means turned to stone or so afraid that one cannot move, "statuesque" means stately and beautiful, and "fervent" means zealous.

"Negligible" means insignificant or unimportant. "Thrifty" means economical or frugal. "Canceled" means called off or erased. "Viable" means reasonable or practical. "Sarcastic" means nasty or mocking in speech. 

"Expendable" means superfluous or unnecessary. "Erudite" means well-educated and cultured. "Dogmatic" means dictatorial or opinionated. "Pedantic" means bookish or overly precise. "Extravagant" means lavish, indulgent, or wasteful. 

"Superficial" and "perfunctory" both mean shallow or trivial. "Analytical" means systematic or examining. "Genuine" means authentic or real. "Profuse" means abundant or excessive. "Somber" means sad or depressing. 

"Elaborate" and "intricate" both mean detailed or complicated. "Facile" means easy or effortless. "Inveterate" means long-standing or established. "Concise" means short and to the point. "Morose" means depressed or pessimistic. 

The word “negligible” is related to “neglect,” though it does not directly mean that. When something is “negligible,” there is so little of it that it is not even worth being thought about. That is, one can neglect thinking about it. It would be used in a sentence like, “The health benefits of running an extra three miles on top of his regular five were so negligible that he decided to forego the extra exercise.” The sense is that they are “insignificant.”

"Ancillary," when used as an adjective, means "providing necessary support to the primary activities or operation of an organization, institution, industry, or system," or "additional; subsidiary." So, "necessary" cannot be the correct answer because it is an antonym of "ancillary." "Supplemental," an adjective that means "something that completes or enhances something else when added to it," is the answer choice closest in meaning to "ancillary," so it is the correct answer.

“Superfluous” means extraneous and unnecessary, so "unnecessary" is the correct answer. As for the other answer choices, “poignant” means touching or moving, making one feel that something is sad and meaningful; “pompous” means arrogant and self-obsessed; “garrulous” means talkative; and "cordial” means polite.

The word "dubious" comes from the same roots as words like "doubt" and "doubtful." The general meaning of these words implies uncertainty. When something is dubious, it is doubtful. Hence, it can seem suspicious. Thus, one might say, "The evidence offered for the argument was dubious. Therefore, the investigator decided to probe further, suspicious that he was being lied to."

Several of these options try to trick you into misreading this word's base. The options "propagating", "green", and "healthy" all try to get you to read "verdant." This word means green and growing healthily. Thus, a "verdant forest" is one that is healthy and green. The word "veridical" actually comes from the Latin root for truth. Think of the word "verify", which means to investigate the truth of the matter. Likewise, the "-dic-" part of this word comes from the Latin for to say or speak, as in words like "dictate" or "diction." Thus, something that is "verdical" is something that speaks the truth. Thus, the correct answer is "truthful."