"Dis-“ is commonly used to mean not in words; however, in this case it means away from while “quiet” means peace or tranquillity. “Disquiet” thus means an emotional state in which peace and tranquility have been taken away—that is, nervousness. The word closest in meaning to "disquiet" is thus “unease,” which is a feeling when you are not at ease—that is, not peaceful or tranquil. The incorrect answer “composure” means one's calmness during a high-stress situation and is thus an antonym of "unease."

The prefix "ig-" is a negative prefix; this means it takes the original meaning of the word and causes it to mean the opposite. So, whereas “noble” means honorable, “ignoble” means not honorable, or "dishonorable." ("Dis-" is also a negative prefix having the same effect on the adjective "honorable.") To provide further help, “parsimonious” means not generous with money; “ostentatious” means pretentious and fancy; “outlandish” means bizarre or weird; and “venerable” means old and well-respected.

“Inhospitable” describes environments and means not suitable to supporting life, so you could say an “inhospitable” place is “harsh.” To clarify, try not to confuse it with “hospital,” although the two words share the same root. “Habitable” refers to environments and means able to be lived in. “Retractable” means easily withdrawn or taken back.

"Certitude" means "Absolute Sureness" or freedom from doubt. "Certitude" comes from the Latin root "cert-" which means sure.

"Recommendation" means the act of presenting something or someone as worth of confidence, use, etc.

"Distrust" means to regard with doubt or not trust.

"Revenue" means the amount of money regularly coming in or income from a property, service or tax.

"Emphasis" means special stress laid upon something, or the act of giving something special importance.

"Omniscient" means having unlimited awareness, so "perceiving all things" is the correct answer. The Latin root "omni-" means all.

"Religious" means related to a religion or related to a belief system that typically involves ritualistic practices.

"False" means not true or correct.

"Omnipotent" means unlimited power.

"Original" means pertaining to the beginning of something.

"Antedeluvian" and "antiquated" have different latin prefixes (ante- meaning before and anti- meaning against). Nevertheless, these words are synonyms referring to a period of time before modernity. "Antiquated" and "antedeluvian" can mean outdated or old-fashioned. The other answer choices do not have this meaning.

The Latin prefix "terra-" means Earth. So, "terrestrial" means of the Earth or related to the Earth. Additionally, "nonchalantly" means done without care or attention; "airborne" means in the air, flying. 

"Contradict" is a verb meaning to deny or be in conflict with. Contra is derived from the Latin root meaning to speak against, so the correct answer will be a synonym meaning to go against. With this in mind, challenge is the correct answer.

“Synthesis” is a noun that means “combination or composition,” and in particular, “the combination of ideas to form a theory or system.” So, we need to pick out an answer choice that means something like “combination.” That means that “dissociation” cannot be the correct answer, because “dissociation” means “the disconnection or separation of something from something else or the state of being disconnected,” making it an antonym, not a synonym, of “synthesis.” “Amalgamation,” however, means “the action, process, or result of combining or uniting,” and because “amalgamation” is the answer choice closest in meaning to “synthesis,” “amalgamation” is the correct answer.

"Amorphous" means without shape or form, so the correct answer is “formless.” For clarification, "shapely" means well-proportioned; "crafty" means sly and sneaky.