1 mole of an ideal monoatomic gas is subjected to the following reversible change of state

$\mathrm{A}\underset{ \mathrm{Expanaion}}{\overset{\mathrm{Isothermal}}{\to }}\mathrm{B}\underset{\mathrm{Cooling}}{\overset{\mathrm{Isochoric}}{\to }}$

(5 atm, 500 K)

$\mathrm{C}\underset{\mathrm{Compreasion}}{\overset{\text{ Adiabatic }}{\to }}\mathrm{A}$

$(300\text{ K) }$

Then, which of the following are correct?