In this sentence, "but" is used as a preposition before a noun, and the full prepositional phrase is "but work."
In the other three sentences, "but" is used as a coordinating conjunction in compound sentence. In these sentences, "but" joins two independent clauses to form a compound sentence.
It is only in sentence B that "but" functions as a preposition.</span>
Answer: The sentence in which "but" is used as a preposition is B. We discovered that Candy will do anything but work.
Explanation: A preposition is a word used to express a relation between two elements in the sentence<u>. Although "but" is mainly used as a conjunction, it can also be used as a preposition. In sentence B., "but" is functioning as a preposition and its meaning is "except"</u>; therefore, what the speaker is trying to say is that Candy will do anything except work. In contrast, in options A., B. and C., "but" has been used as a conjunction.
