Which of the Following Is Not a Real Difference Between

Which of the following is not a real difference between asteroids and comets?

A) Asteroids orbit the Sun while comets just float randomly around in the Oort cloud.
B) Most asteroids are located much nearer to the Sun than most comets.
C) It is thought that comets are far more numerous than asteroids.
D) Asteroids are made mostly of rock and comets are made mostly of ice.