Which option is a compound sentence?

Question

A.
We went to the railroad station, but the train had already departed.

B.
Her friend sent her a text message after the game ended.

C.
My dog Raffi played with other dogs at the dog park today.

D.
Since we left home in a hurry, we forgot to lock the door.

Answer 1

A. We went to the railroad station, but the train had already departed.

This option is a compound sentence because it contains two independent clauses ("We went to the railroad station" and "the train had already departed") joined by the coordinating conjunction "but."