[单选题]
Ball A is dropped from the tq2k1 w c4t2xa/3z nqecop of8bmz0xp w1 8qo9dq q3rwqv44 r a building. One second later, ball B is dropped from the same building. As time progresses, the w9rqq 3 r01bq488dq xwmzv4opdifference in their speeds
A. increases.
B. remains constant.
C. decreases.
D. cannot be determined from the information given.
