The correct order of events in the formation of our solar system is as follows:
- A solar nebula began to spin and collapsed under its own gravity.
- As it collapsed, it pulled in more gas and flattened into a rotating disk.
- The solar nebula spun faster and faster.
- Most of the gas was pulled toward the center of the disk, where it became hot and dense, ultimately forming the Sun.
So, the last option you provided most accurately reflects the sequence of events:
"The solar nebula spun faster and faster and flattened into a rotating disk. Most of the gas was pulled toward the center, where it became hot and dense, forming the Sun."