Two ideal gases, each consisting of N
monatomic molecules, are in thermal equilibrium
with each other and equilibrium is maintained as
the temperature is increased. A molecule of the
first gas has mass m and a molecule of the
second has mass 4m. The ratio of the changes in
the internal energies ∆E4m/∆Em is -
(A) 1/4 (B) 1/2
(C) 1 (D) 4