A Spaceship Is Moving Away from an Asteroid with a Speed

Multiple Choice

A spaceship is moving away from an asteroid with a speed of 0.80c relative to the asteroid. The spaceship then fires a missile with a speed of 0.50c relative to the spaceship. What is the speed of
The missile measured by astronauts on the asteroid if the missile is fired away from the asteroid?

A) 0.50c
B) 0.65c
C) 0.93c
D) 0.30c
E) 1.3c