Which of the Following Describes a Star with a Hydrogen-Burning

Multiple Choice

Which of the following describes a star with a hydrogen-burning shell and an inert helium core?

A) It is a red giant that grows in luminosity until it dies in a planetary nebula.
B) It is a subgiant that gradually grows dimmer as its hydrogen-burning shell expands and cools.
C) It is a subgiant that grows in luminosity until helium fusion begins in the central core.
D) It is what is known as a helium-burning star,which has both helium fusion in its core and hydrogen fusion in a shell.