Answer:
nuclear fusion
Explanation:
When the density and temperature at the core of the gravitationally collapsing nebula reaches values when nuclear fusion is triggered and sustained, that marks the birth of the star.
Gravity: A force that keeps things in place sonit doesnt float around.
Mass: The amount of matter or substance that makes up an object
Weight: How heavy or light something is
Inertia: property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force.
Answer: Ask your teacher for some help
Explanation: if anything can help us your teacher
According to my research it’s C: Nucleus