Answer:
Sorry to ask you but I kind don't understand what you are trying to ask me
Explanation:
The phrase <em>with exciting plots </em>is used as D. adjective phrase, because it modifies the noun <em>books.
</em>What kind of books? - (The ones) with exciting plots. <em>
</em>
The correct answer is A, WHEN THEY ARRIVED AT THE BEACH.
In English language, an adverb is one of the part of speech. An adverb is a part of speech that talk more or qualifies a verb. It can also be used to qualify an adjective, another adverb or a clause. An adverbial dependent clause refers to an adverbial clause that can not stand alone. In the question given above, the statement given in option A is an adverbial clause, which quality the verb 'arrived'.