The sentence as constructed does not actually contain a verb. "Having" in this sentence is the present participle, which always needs a form of the verb "to be." In this sentence, the appropriate form is "are," the plural form, making "The girls are having a party" the correct answer.

The use of "marching" makes the sentence not have a verb, as the participle form always needs some form of the verb "to be" used immediately before it to make it a complete verb. (For example, it's not grammatically correct to say "The fish swimming across the lake." Anyone who heard this might ask, "The fish swimming across the lake did what?" since "swimming" is a participle—a verb acting like an adjective. Instead, the correct way to say this would be, "The fish was swimming across the lake," or, alternatively, use a different verb form altogether, such as "The fish swam across the lake." To correct the problem's sentence, either the participle "marching" needs to be preceded by some form of the verb "to be," or it should be changed to some other form than the present participle to avoid functioning as an adjective and instead clearly function as the sentence's verb. The only answer choice that uses either of these options is "The battalion marches towards the battlefield on their way to the conflict."

The use of "much" in the sentence is incorrect, as "much" indicates a great amount, but not a large count, and should be used for singular nouns. The correct choice should have the word "many" instead of "much." The only answer choice that makes this chnage is "despite many different attempts to do so."

The use of the adverb "unpredictably" is incorrect in the sentence, as it describes a noun and should be an adjective. Otherwise, the sentence is absolutely correct; therefore, the best answer choice is "as it can be unpredictable."

The underlined portion of the sentence problematically contains a misused adverb, "strongly." This needs to be turned into an adjective to appropriately describe "desire." "Have a strong desire" is the only answer choice that does this and is fully gramatically correct.

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."