Equal Volumes of Hydrogen and Helium Gas Are at the Same

Equal volumes of hydrogen and helium gas are at the same pressure. The atomic mass of helium is four times that of hydrogen. If the total mass of both gases is the same, the ratio of the temperature of helium (He) to that of hydrogen (H₂) is

A) .
B) .
C) 1.
D) 2.
E) 4.