The word "cogent" is generally used to describe an argument that someone might be making. It means logical or convincing. An example sentence would be, "After he presented the facts, his argument seemed to be quite cogent. Therefore, I agreed with his decision and followed his instructions." Such an argument is also "compelling," meaning something like irresistible—as though the argument is so strong that it cannot be "overcome."

"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.

"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.

The word "intuition" literally means to see into. It was originally used to describe the way that the senses are aware that something is present to us directly. It has come to mean something more like a non-conceptual understanding. To have an "intuition" is to have a "sense" that something is the case, even though you cannot put it into words. Therefore, the best synonym for "intuitive" is the word "instinctive," for an "intuitive" action is one that is almost by instinct (instead of thought).

"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.

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.

"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.

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."

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.”

“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.