Answer:
D. Dad went into the bedroom, but first he stopped to pet the dog.
Explanation:
A coordinate clause is a clause introduced by one of the coordinating conjunctions (<em>for, and, nor, but, or, yet, </em>or <em>so</em>). Together with the main clause, one or more coordinate clauses make up a compound sentence - a sentence that consists of two or more independent clauses.
In order to solve this question, we need to determine which sentence contains a coordinating conjunction. Based on the list of coordinating conjunctions I've included, we can see that the correct answer is sentence D (<em>but </em>is the coordinating conjunction that introduces the coordinate clause). The rest of the sentences contain subordinating conjunctions (<em>although, if, after</em>), which is why they are incorrect.
This is why option D is the correct one.
