Question

what is the final event that occurs when a star is forming?
the outer layer of the star expands
gravity pulls gas and dust together
a black hole forms as the core collapses
nuclear fusion begins under high pressure

Explanation:

When a star is forming, gravity pulls gas and dust together. The outer layer expanding occurs during other stages (like in some evolved stars), a black - hole forming as the core collapses is a late - stage event for massive stars (not during formation), and nuclear fusion begins under high pressure is a later step in the star - formation process after the initial gathering of gas and dust by gravity.

Answer:

Gravity pulls gas and dust together.