[单选题]
Relative to a stationary observer, a movi .ay0ir0aa xs,fq-0ag ng cloc4( 3zcc buj7pauqx p/)w8.7b*a b naobk
A. always runs slower than normal.
B. always runs faster than normal.
C. keeps its normal time.
D. can do any of the above. It depends on the relative velocity between the observer and the clock.
