In a car race on straight road, car A takes a time t less than car B at the finish and passes finishing point with a speed ' v ' more than of car B. Both the cars start from rest and travel with constant acceleration a1 and a2 respectively. Then ' v ' is equal to:
a. a1+a22a1a2t
b. 2a1a2t
c. a1a2t
d. 2a1+a2t