33. A thermally insulated chamber has two equal-volume compartments with a movable insulated partition in between. Initially one compartment contains two moles of helium gas at T = 100 K, and the other compartment contains one mole of argon gas at T = 400 K. Assume that both gases can be considered ideal gas. What is the total change of entropy of the system after the compartment has been removed and the gases have reached a new equilibrium?
(A) 1.5Rln2
(B) 3Rln2
(C) 4.5Rln2
(D) 6Rln2
(E) none of the above.