[单选题]
Relative to a stationary tz /z5m9b i ur-fkw37+lps5i2z unr w1obse5yuq2z8xhgk 2rver, a moving object
A. appears shorter than normal.
B. appears longer than normal.
C. keeps its same length time.
D. can do any of the above. It depends on the relative velocity between the observer and the object.
