[单选题]
Ball A is dropped from thm4 aypx,p8h,5lar cy+ e qo*fgcq2z x.* top of a building. One second later, ball B is dropped from the same building. * o q.c*qgfzx2As time progresses, the distance between them
A. increases.
B. remains constant.
C. decreases.
D. cannot be determined from the information given.
