Consider two less-than-desirable options.
In the first, you are driving 30 mph and crash head-on into an identical car also going 30 mph. In the second option, you are driving 30 mph and crash head-on into a stationary brick wall. In neither case does your car bounce off the thing it hits, and the collision time is the same in both cases.
Which of these two situations would result in the greatest impact force?
Choose one answer.

a) hitting the brick wall
b) hitting the other car
c) The force would be the same in both cases.
d) We cannot answer this question without more information.
e) None of these is true.

The change in momentum is known as an impulse. In the two cases under consideration, the change in momentum is the same, thus impulse for both cases is the same.

Impulse is the average force multiplied by time interval.

I = F(average)*ΔT. Where F(average) is the average force and ΔT is the time interval.

The average force in both cases is the same since the collision time is the same.

Thus option C is the correct answer.