Which statement below is not TRUE:

a$.$

The critical gap is the gap which $50\%$ of drivers would accept to merge or cross.

b$.$

In the gap acceptance behaviour, the follow$-$up gap is always less than the critical gap

c$.$

The critical gap is the smallest accepted gap that is recorded in a gap$-$acceptance survey.

d$.$

Unsignalized intersections, roundabouts, and pedestrian crossing movements all function through a gap acceptance mechanism.

e$.$

None of the other answers are correct