One kg of a diatomic gas is at a pressure of $8 \times 10^4\;N/m^2$. The density of the gas is $4\; kg/m^{3}$. What is the energy of the gas due to its thermal motion ?

Question

( A ) $7 \times 10^4$ J
( B ) $3 \times 10^4$ J
( C ) $5 \times 10^4$ J
( D ) $6 \times 10^4$ J