Most Meteoroids-- Rocks Moving Through Outer Space--Have Been Moving for Billions

Most meteoroids-- rocks moving through outer space--have been moving for billions of years. What, if anything, keeps them moving and why?

A) According to Newton's law of motion, their own acceleration keeps them moving.
B) According to Newton's law of gravity, the force of gravity keeps them moving.
C) According to the law of inertia, nothing is needed to keep them moving.
D) According to current theories about the creation of the universe, the big bang keeps them moving.
E) According to Newton's law of gravity, nothing is needed to keep them moving.