Two Astronauts, of Masses 60 Kg and 80

Multiple Choice

Two astronauts, of masses 60 kg and 80 kg, are initially right next to each other and at rest in outer space. They suddenly push each other apart. What is their separation after the heavier astronaut has moved 12 m?

A) 28 m
B) 24 m
C) 9.0 m
D) 16 m
E) 21 m