As a Rocket Ship Moves by at 0

Multiple Choice

As a rocket ship moves by at 0.95c a mark is made on a stationary axis at the front end of the rocket and 9.0 * 10^-8 s later a mark is made on the axis at the back end.The marks are 100 m apart.The rest length of the rocket is:

A) 31 m
B) 78 m
C) 100 m
D) 240 m
E) 320 m