Someone in Earth's Rest Frame Says That a Spaceship's Trip

Multiple Choice

Someone in Earth's rest frame says that a spaceship's trip between two planets took 10.0 y,while an astronaut on the spaceship says that the trip took 6.27 y.Find the velocity of the spaceship in terms of the speed of light.

A) 0.779 c
B) 0.687 c
C) 0.975 c
D) 0.384 c