When a bicycle is in motion,the force of friction exerted by the ground on the two wheels is such thatit acts(a) In the backward direction on the front wheel and in the forward direction on the rear wheel.(b) In the forward direction on the front wheel and in the backward direction on the rear wheel.(c) In the backward direction on both the front and rear wheels.(d) In the backward direction on both the front and rear wheels.

• A. a
• B. b
• C. c
• D. d