Choose the sentence with correct use of the adverbial clause:
A. Because it was raining, the event was moved indoors.
B. Because was raining, the event was moved indoors.
C. Because it was raining, event was moved indoors.
D. Because it was raining the event was moved indoors.
The correct form is "Because it was raining, the event was moved indoors," using the adverbial clause to explain the reason for moving the event.