[单选题]
The length of a spaceship is 10 m when i i-;0xqr 5qwl(bmc oj/ n6ht s 666c0pdytcn+st is at rest. If the spaceship travels b6t6ndh 0nc6 c+tpys6sy you 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. $18 \; m$
