Refer to this sentence to answer the question.
Antonio couldnāt go to the store because the road was closed.
What is the purpose of the subordinate conjunction ābecauseā?
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 couldnāt go to the store.
C. It separates the subject from the verb.
D. It separates the subject from the predicate.