Answer:
b) Distance covered before stopping.
Explanation:
If you want to find the distance d required to come to a stop starting at some initial speed v, with braking acceleration a, use the kinematic relation
vf2 - vi2 = 2ad
vi = initial speed at the moment braking begins = v
vf = final speed = 0 (comes to a full stop)
-v2 = 2ad
d = -v2/(2a)