Which of the following is an example of a compound sentence?

A compound sentence consists of two or more independent clauses joined by a coordinating conjunction, such as "and," "but," or "or." In the correct choice, the sentence "I wanted to eat, but I was not hungry" contains two independent clauses: “I wanted to eat” and “I was not hungry.” These clauses can stand alone as complete sentences, and they are connected by the coordinating conjunction "but," which indicates a contrast between the two ideas.

The other options do not fit the criteria for a compound sentence. The first choice is a simple sentence with just one independent clause. The second choice features a dependent clause ("Although it was raining") and an independent clause, thereby making it a complex sentence rather than a compound sentence. The last choice also contains a dependent clause ("When the sun sets") and an independent clause, categorizing it as another example of a complex sentence. Therefore, the right option clearly illustrates the structure of a compound sentence.