P and Q are ideal gases which do not react with each other. The mass of one mole of P is four times that of Q. At STP, which of the following are true?

Options

A. The average K.E of molecules of P is equal to that of Q
B. The mass of 1 `dm^3` of P is four times that of 1` dm^(3)` of Q
C. On mixing 1`dm^(3)` of P with 1`dm^(3)` of Q the partial pressure of each gas in the mixture will be 0.5 atm
D. The rate of diffusion of P is 4 times less than that of Q