Question

according to the nebular theory, what was our solar system before it became our solar system?
a supernova
a large black hole
a cloud of dust and gas
a giant cluster of asteroids

Explanation:

The nebular theory states that the solar system formed from a rotating cloud of dust and gas called a nebula. A supernova is an explosion of a star. A black hole is a region in space with extremely strong gravitational pull. A giant cluster of asteroids is a collection of rocky bodies in space. None of these (supernova, large black hole, giant cluster of asteroids) are what the solar system was before its formation according to the nebular theory.

Answer:

a cloud of dust and gas