Pe=1/2Kx^2
Half times spring constant times distance squared over time
We have: v = d/t
From the expression, we conclude speed is indirectly proportional to speed.
So, the car which will take longer time must have the smallest speed. Among all the options Car C has the smallest speed. So, it would be your answer.
In short, Your Answer would be Option C) Car C will take longer time than any other.
Hope this helps!
Meters would be the best way to record the length