[单选题]
Ball A is dropped from the top of a building. y 5 5rbw-j5zqz One sec .) hxfz.ofh37kskwz9 ond later, ball B is dropped from the same builo3 .97f. )fh wzzhsxkkding. As time progresses, the distance between them
A. increases.
B. remains constant.
C. decreases.
D. cannot be determined from the information given.