The use of the word "frighteningly" is absolutely incorrect, as it is an adverb being used to describe a gerund, or a verb that takes the form of a noun, in "looking." Gerunds need to be modified with an adjective. Therefore, "to the frightening looking motel" is the correct answer.

The two words "many" and "much" mean the same thing, "a lot of," but are used in two distinct ways. "Many" is used exclusively with counting nouns, while "much" is used with noncounting nouns; therefore, when used with "detail," "much" is correct, while "many" would be correct with "details."

The answer choice "otherwise you will not appreciate the equally poignant sequel" is another subordinate clause, so this answer choice is incorrect because it leaves the sentence with no independent clause.

In the answer choice "you will not appreciate the equal poignant sequel," "equal" is an adjective, but you must choose an adverb that modifies the adjective “poignant." "Equally" is the correct form, so this answer choice is incorrect.

The answer choice "only after fully appreciating the equally poignant sequel," is another subordinate clause, so this answer choice is incorrect. You must pick an independent clause.

In the answer choice "you did not appreciate the equally poignant sequel,"the past tense form of “did appreciate” does not agree with the insubordinate clause, which indicates that something will happen in the future (after you comprehend the message). The appropriate choice should indicate somethign that occurrs in the future, so this answer choice is incorrect.

The answer choice "you will not appreciate the equally poignant sequel" is a future-tense independent clause with the appropriate adverb form of "equally." It is correct!

The use of the word "simultaneous" actually describes the verb "developed," even though it is next to the verb "researchers." The issue can be corrected by making the word "simultaneous" an adverb. "By two researchers simultaneously" is the correct answer choice.

The use of the adverb "horribly" is wrong, as the word modifies a noun, "comedian," and should actually be an adjective. This problem can be corrected by shifting "horribly" to its adjectival form. Therefore, the correct answer choice is "He was a horrible comedian, with no ability to make anybody laugh."

The use of the adjective "perfect" is incorrect in this sentence, as it modifies the verb "handled." A verb can only be modified by an adverb, meaning "perfect" must be changed to its adverbial form. As the only answer choice to use the adverb "perfectly" instead of the adjective "perfect," the correct answer choice is "as it always handled its money perfectly."

The use of the adverb "thoughtfully" is incorrect here, as it is being used to modify the noun "consideration." Adjectives, not adverbs, are used to modify nouns. The correct phrase is therefore "giving it thoughtful consideration," which uses the adjective "thoughtful" instead of the adverb "thoughtfully."

The word "alleged" is modifying the word "made," a verb, which needs an adverb to modify it. The adverb form of "alleged" is "allegedly," which makes the correct answer "allegedly made."

The use of the word "usual" in the sentence is incorrect, as it describes the verb "took," which means it needs to take an adverb form. The only answer choice with the correct form that also keeps the intended meaning of the sentence is "The old man usually took."

The word "increasing" in the sentence is used to describe the verb phrase "being delayed." Even though these words are not the verb in the sentence, they still need an adverb form to describe them. The correct answer is "Marriages are increasingly being delayed."