[单选题]
A car starting from rest movevy/ey/oy ,.yb s with constant acceleration oegj//i *3qgb-q(,oz u+ zvq mzf $2.0 \; m/s^2$ for 10 s, then travels with constant speed for another 10 s, and then finally slows to a stop with constant acceleration of -$2.0 \; m/s^2$. How far does it travel?
A. $200 \; m$
B. $300 \; m$
C. $400 \; m$
D. $500 \; m$