[单选题]
A car decelerates un)d lj37n,;zfvljn p8i srpbx 34d b.9miformly and comes to a stop afte(m( 4b ,rvniw4izfoia w1))kvr 10 s. The car's average velocity during deceleration was 50 km/h. What was the car's deceleration(,n vi1) z4v worm)afbi i4wk( while slowing down?
A. 10 km/h/s
B. 8.0 km/h/s
C. 5.0 km/h/s
D. 4.0 km/h/s
