[单选题]
The length of a spaces:r6u r )zh7ulofncoq*4 a7uzpg)vl;- hip is 10 m when it is at rest. If the spaceship travels by you with a speed of 0.70c, what length does it appear to g 7p-vuaqf)z *o;c4lnyou?
A. $5.5 \; m$
B. $7.1 \; m$
C. $12 \; m$
D. $18 \; m$