Answer
a) greater than
b) III
Work Step by Step
(a) We know that the stopping distance of driver 1 is greater than that of driver 2. The reason behind this is that driver 1 stops the car using kinetic friction while driver 2 uses static friction. Thus driver 2 has a larger braking force and the car stops quickly.
(b) We know that the correct option is statement III -- that is, locked up brakes use sliding (kinetic) friction, which is less than rolling (static) friction.
