Which one of the options given below, correctly combines the following two sentences into a Compound sentence? The sky was clear. The sun was setting.

The sky was clear while the sun was setting

The sky was clear, and the sun was setting

The sky was clear, for the sun was setting

None of these

The sky was clear, and the sun was setting.

A compound sentence joins two independent clauses using a coordinating conjunction like "and."

Here, both "The sky was clear" and "The sun was setting" are independent clauses combined with "and."