[单选题]
The length of a spaceship is 10 m whneic /j)+wtc )s-ga ;ten it is at rest. If the s7xo9 wd,ft, f4te ;odmnty5zw.-e nj9paceship travels by you with a speed of 0.70c, what length does wj dwn;my 5xt-,o 9on t ,4e9tfz7f.deit appear to you?
A. $5.5 \; m$
B. $7.1 \; m$
C. $12 \; m$
D. $18 \; m$
