At the end of the first down, the Chargers had the ball on their 25-yard line. On the next three downs, they lost 8 yards, gained 13 yards, and lost 8 yards. How many yards from the Chargers' zero-yard line is the ball at the end of the fourth down?
A) 32 yards
B) 38 yards
C) 40 yards
D) 42 yards