Which sentence is an example of a compound sentence?

A compound sentence is characterized by having at least two independent clauses that are connected by a coordinating conjunction. In the example given, "He likes coffee, and she prefers tea," there are two independent clauses: "He likes coffee" and "she prefers tea." Each clause has its own subject and verb and can stand alone as a complete sentence. The use of the conjunction "and" effectively connects these clauses, making it a compound sentence.

In contrast, the other options consist of single clauses that do not connect two independent thoughts, thus making them simple sentences rather than compound sentences. They do not fulfill the requirement of having multiple independent clauses joined by a conjunction.