Rigorous means demanding or challenging. This can be determined from the context of the sentence. Manuel is worried about the test. That should eliminate easy as answer. A test can't really be "obnoxious," which means badly behaved or overly loud. That leaves "long" and "demanding." "Long" can be eliminated because a long, but easy, test probably wouldn't make Manuel nervous that he hadn't studied enough.

"Lethal" means deadly, can cause death. To provide further help, "fortunately" and "luckily" both mean the same thing, they are synonyms of one another. On the other hand "gently" which means done carefully and calmly, is the opposite of "carelessly" which means done without care. "Gently" and "carelessly" are antonyms of one another.

The words "carnivorous" and "flesh-eating" are synonymous. These words refer to something that eats meat or flesh. The words "herbivorous" and "vegetarian refer to something that eats plants instead of eating meat. The words "fancy" and "elegant" are synonymous with each other; they refer to something that is decorated or refined.

The word most similar in meaning to RIDICULOUS is "silly." "Ridiculous" means inviting mockery. If you wore a ballet outfit with swimming goggles to school, you might look ridiculous. You would also look "silly!"

To determine the meaning of "incomparable," use the base word "comparable." This is similar to the word "compare." "Comparable" means things are roughly equal. Now add the prefix "in" which means not. "Incomparable" means not equal or outstanding. For example: "For the concert tonight, I am announcing the incomparable Taylor Swift."

"Creative" means to be imaginative.

If you are "descriptive," you "describe."

"Dynamic" means constantly changing.

Since "absurd" is an adjective that means "silly," we need to pick out another adjective that means "silly." While "serious" may look like the correct answer, it actually means the opposite of "silly." However, "ridiculous" is an adjective that means "extremely silly or unreasonable," so "ridiculous" is the correct answer.

“Fundamental” is an adjective that means “forming a necessary base or core; of central importance,” so we need to pick out an answer choice that means something like “important.” That means that “trivial” cannot be the correct answer, because “trivial,” is an adjective that means “of little value or importance,” making it an antonym, not a synonym, of “fundamental.” “Crucial,” however, is an adjective that means either “decisive or critical, especially in the success or failure of something” or “of great importance,” and because “crucial” is the answer choice closest in meaning to “fundamental,” “crucial” is the correct answer.

"Latent" means dormant or hidden.

"Artificial" and "fake" both have a similar meaning.

"Unbelievable" means incredible.

"Essential" is an adjective that means necessary, so "necessary" is the correct answer.