What Leads Astronomers to Conclude That the Proto-Galactic Cloud (The

What leads astronomers to conclude that the proto-galactic cloud (the cloud from which our Galaxy formed) was roughly spherical?

A) all black holes have spherical event horizons
B) the shape of the disk and spiral arm of the Milky Way Galaxy is spherical, so the original cloud must have been too
C) the oldest stars in the Galaxy (Population II stars, globular clusters) form a spherical halo around the Galaxy; they outline the original shape of the cloud that gave the Galaxy birth
D) since the Big Bang that made everything was spherical, all structures in the universe must also be spherical
E) actually, astronomers believe the original proto-galactic cloud was in the shape of a flat disk, like the Galaxy is now