[单选题]
Ball A is dropped from the top of a x,nee93tc3 uuy;0rwm-1angebuilding. One second later, ball B is dy(nm c3tz ,wf;ropped from the same building. As time progresses, t3,cm;y(nzf tw he distance between them
A. increases.
B. remains constant.
C. decreases.
D. cannot be determined from the information given.
