[单选题]
The length of a spaceship is 10 mzja8el / :ey el,zm6w. qn+we4;slm,y when it is am igrb66 pb :mcq,wac0(fi86 t+ztlnx*vj,r7 t rest. If the spaceship travels by wmtl(r6itn*6bczmgbv:+a if0 7rx,cp, 6 jq8you with a speed of 0.70c, what length does it appear to you?
A. $5.5 \; m$
B. $7.1 \; m$
C. $12 \; m$
D. $18 \; m$
