An Astronaut Leaves Earth in a Spaceship at a Speed

Multiple Choice

An astronaut leaves Earth in a spaceship at a speed of 0.960c relative to an observer on Earth. The astronaut's destination is a star system 14.4 light-years away (one light-year is the distance light travels in one year.) According to the astronaut, how long does the trip take?

A) 14.4 y
B) 22.7 y
C) 9.34 y
D) 15.0 y
E) 4.20 y