[单选题]
A cart starts from res0pdlk9p8)cy e:8ux4bg j lva t ro1m58t and accelerate; ba+mzi35sq es at $4.0 \; m/s^2$ for 5.0 s, then maintain that velocity for 10 s, and then decelerates at the rate of $2.0 \; m/s^2$ for 4.0 s. What is the final speed of the car?