The correct choice is (a) 0.7î + 0.55ĵ
For explanation: The velocity of a body is the rate at which the displacement changes with time. Here, the change in position is the change in displacement, and is 14î + 11ĵ. The total time taken is 20s. Hence, the acceleration = change in displacement/time = 0.7î + 0.55ĵ.