A quarterback is sacked for a loss of 5 yards. On the next play, his team loses 15 yards. Then the team gains 12 yards on the third play. Write an addition expression to describe this situation.
A. -5 + (-15) + 12
B. 5 + (-15) + 12
C. -5 + 15+ ( - 12)
D. 15 + 7
Which expressions are correct.