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 space ship says that the trip took
What is the speed of the spaceship,assuming the planets are at essentially at rest?

A) 0.816 c
B) 0.735 c
C) 0.975 c
D) 0.384 c