Refer to this sentence to answer the question.

Antonio couldn’t go to the store because the road was closed.

What is the purpose of the subordinate conjunction “because”?

A. It signals that the sentence is about to explain why the road was closed.

B. It signals that the sentence is about to explain why Antonio couldn’t go to the store.

C. It separates the subject from the verb.

D. It separates the subject from the predicate.