question_answer

For years, space travel was believed to be impossible because there was nothing which rockets could push off of in space in order to provide the propulsion necessary to accelerate. This inability of a rocket to provide propulsion is because:

A)  Space is void of air so the rockets have nothing to push off of

B)  Gravity is absent in space

C)  Space is void of air and so there is no air resistance in space

D)  Rockets do accelerate in space and have been able to do so for a long time

E)  None of these