31.A star will compress itself into a white dwarf, a neutron star, or a black hole after it passes through a red giant stage, depending on mass.
(A) A star will compress itself into a white dwarf, a neutron star, or a black hole after it passes through a red giant stage, depending on mass.
(B) After passing through a red giant stage, depending on its mass, a star will compress itself into a white dwarf, a neutron star, or a black hole.
(C) After passing through a red giant stage, a star's mass will determine if it compresses itself into a white dwarf, a neutron star, or a black hole.
(D) Mass determines whether a star, after passing through the red giant stage, will compress itself into a white dwarf, a neutron star, or a black hole.
(E) The mass of a star, after passing through the red giant stage, will determine whether it compresses itself into a white dwarf, a neutron star, or a black hole.

OA is D

How to attack this ques? what is essential and what is not essential part in the sentnce. How to determine whether "passing thorugh a red giant phase" or "mass" is essential in the above sentence?