Two cars, $A$ and $B$, start side by side and accelerate from rest. The figure shows the graphs of their velocity functions.

(a) Which car is ahead after one minute?

A. It is impossible to determine which car is ahead.
B. Car $B$.
C. Both cars are still side by side.
D. Car $A$.

(b) What does the area of the shaded region represent?

A. The distance by which Car $A$ is ahead of Car $B$.
B. The distance that Car $A$ has traveled.
C. The distance traveled by both cars.
D. The distance that Car $B$ has traveled.
E. The distance by which Car $B$ is ahead of Car $A$.

(c) Which car is ahead after two minutes?

A. Car $B$.
B. It is impossible to determine which car is ahead.
C. Both cars are now side by side.
D. Car $A$.

(d) To within one decimal place, estimate the time (in minutes) at which the cars are again side by side.

Time = minutes