A Few of the Largest Asteroids Appear to Be Spherical

A few of the largest asteroids appear to be spherical.How do you think they got this way?

A) The visible outer atmospheres of these large asteroids are spherical, even though the underlying surfaces are irregular.
B) The largest asteroids solidified from spherical gas clouds in their early history and retained this shape.
C) Repeated collisions with other asteroids have worn the largest asteroids down to spheres.
D) Self-gravity was sufficient to pull the largest asteroids into a spherical shape during their early history.