What Major factors determines the Stage that a star completes in its cycle

The major factor that determines the stage that a star completes in its cycle is done by its mass.

Explanation:

The life cycle of star is determined by its mass. The mass of the star is calculated by the amount of matter that is present in the nebula.

At first star begins is life as a cloud of dust and gas known as nebula. A protostar is formed while the gravity caused the dust and gas of a nebula to combine together in a process called accretion. If the protostar reaches the critical temperature then nuclear fusion begins and star is born.

The stars die because they exhaust their nuclear fuel. If there is no fuel left, the star collapses and the outer layer explode as a 'supernova'.

There are seven stages of a star they are A giant gas cloud, A protostar is a baby star, T-Tauri phase, main sequence stars, Expansion into red giant , Fusion of heavier elements and supernovae and planetary nebulae.

answer; ///(b) it is composed of four protein chains and four heme groups;