The reversible expansion of an ideal gas under adiabatic and isothermal conditions is shown in the figure. Which of the following statement(s) is (are) correct ?

A

$$T_1 = T_2$$

B

$$T_3 > T_1$$

C

$$W_{isothermal} > W_{adiabatic}$$

D

$$\triangle U_{isothermal} > \triangle U_{adiabatic}$$