Combine the following sentences using a subordinate conjunction. Sentence: Supper won't be ready for another half hour. We have time for a bit of ping pong.

A: Supper won't be ready for another half hour, so we have time for a bit of ping pong.

B: Since supper won't be ready for another half hour, we have time for a bit of ping pong.

C: Supper won't be ready for another half hour, we have time for a bit of ping pong.