How Do Asteroids Differ from Comets

How do asteroids differ from comets?

A) Asteroids are rocky bodies and are denser than the comets,which are made of icy material.
B) Asteroids are rocky bodies and are less dense than the comets,which are made of icy material.
C) Asteroids are made of icy material and are denser than the comets,which are more rocky.
D) Asteroids are made of icy material and are less dense than the comets,which are rockier.
E) Asteroids and comets are both made of rocky and icy material,but asteroids are smaller in size than comets.