In a Small-Overlap Front Crash Test, a Car Is Crashed

In a small-overlap front crash test, a car is crashed into a simulated telephone pole and the maximum intrusion of debris into the passenger compartment of a specific model of car is Measured. This intrusion is normally distributed with a standard deviation of 2.5 cm.
How many cars must be crashed to establish that a 98% confidence interval for the mean intrusion of Debris into the passenger compartment will have a margin of error of 0.3 cm?

A) 49
B) 376
C) 1
D) 20