[单选题]
Ball A is dropped from nd*j+m h*i(jfa0f q:n the b fklf am02iamu8--c :top of a building. One second later, ball B is dropped from the same building. As time progresses, the differeuk:-20aclibfa-mf m 8nce in their speeds
A. increases.
B. remains constant.
C. decreases.
D. cannot be determined from the information given.
