[单选题]
Ball A is dropped from ta j(q( ,xs2kikhe top of a building. One secondvq+fbb v;z5+j later, ball B is dropped from the same building. As time progresses, the difference in thejb ;5 qf+z+vvbir speeds
A. increases.
B. remains constant.
C. decreases.
D. cannot be determined from the information given.
