"Feral" means untamed, or "wild."

"Terse" means using very few words in order to make a point. "Concise" means using the minimum amount of words to communicate an idea. Given the similarities in meaning between these words, they are synonyms. While "terse" and "tense" may sound similar, they have different meanings and therefore are not synonyms.

"Spontaneous" is an adjective that means "performed or occurring as a result of a sudden inner impulse or inclination and without premeditation or external stimulus," so we need to pick out a word that means about the same thing - roughly, "unplanned." While "premeditated" might seem like a good answer because like "spontaneous," it has to do with preparation, "premeditated" actually means "thought out or planned beforehand" and often is used to refer to crimes. So, "premeditated" is an antonym of "spontaneous" and is not the word we're looking for. "Extemporaneous," on the other hand, is an adjective that means "spoken or done without preparation," and since it is closest in meaning to "spontaneous," it is the correct answer.

Since "cantankerous" means "bad-tempered, argumentative, and uncooperative," we're looking for another adjective that means "bad-tempered." While "condescending" may sound like a potentially correct answer, "condescending" actually means "having or showing a feeling of patronizing superiority." Since "condescending" doesn't mean "bad-tempered," it can't be the right answer. "Querulous," however, means "complaining in a petulant or whining manner," and because it is the answer choice closest in meaning to "cantankerous," it is the correct answer.

"Belligerent" is an adjective meaning "angry and aggressive; feeling or showing readiness to fight," so we should pick out another word that means "aggressive." While "assertive" and "confrontational" might both look like potentially correct answers, "confrontational" is the better answer. This is because "assertive" means "confident in behavior in style," and is thus not a synonym of "belligerent," while "confrontational" means "tending to deal with situations in an aggressive way; hostile or argumentative," which is synonymous with "belligerent."

"Obdurate" is used to describe someone that is stubborn or headstrong. Adamant is a synonym of Obdurate. Submissive and Docile are antonyms of Obdurate because they describe someone that is easy to control. Affluent means wealthy and Placid means calm and tranquil. Both of these words have no relation to Obdurate.

"Prudent" means to be careful, so that would be the synonym. Rash and Reckless have the opposite meaning of prudent. Grandiose describes something or someone that is overly showy. Well-known describes something or someone that known my many people. These last two words have no relationship to Prudent in this instance.

"Boisterous" means to be loud and unrestrained. Subdued and Quiet have the opposite meaning of Boisterous. Commodious means to be roomy, and Deft means to be skilled. These two words have no relation to the Boisterous.

"Petulant" describes someone that is easily irritated, so Irritable would be the correct answer. Patient is the opposite of Petulant. Bloated means something or someone is swollen. Dangerous describes something or someone that can cause harm, and Pugnacious means belligerent or warlike. These last three words have no relation to Petulant in this context.

Hearty means heartful, or loud and cheerful.