It is answer B, that is what I think it is
Answer: Gravity made the dust and gas in the nebula collide, flattening these materials into a disk.
Explanation: The nebula theory is a scientific explanation of how the planets and our solar system were formed. It suggests that our solar system was formed more than 4 billion years ago due to the effect of gravity on a cloud of gas and dust which were flattened into a disk. The gravity was so great that the matter in the nebula were made to collide against each other until they were compacted to form our sun.
