As a White Dwarf Cools Its Radius Does Not Change

As a white dwarf cools its radius does not change because

A) pressure due to nuclear reactions in a shell just below the surface keeps it from collapsing.
B) pressure does not depend on temperature for a white dwarf because the electrons are degenerate.
C) pressure does not depend on temperature because the white dwarf is too hot.
D) pressure does not depend on temperature because the star has exhausted all its nuclear fuels.
E) material accreting onto it from a companion maintains a constant radius.