Thermodynamics (Carnot Cycle)

For 1.0 mol of an ideal gas a reversible cycle has four steps: process 1 is isothermal at T1 from state 1 (p1,V1,T1) to state 2 (p2,V2,T1); process 2 is adiabatic from state 2 to state 3 (p3,V3,T2); process 3 is isothermal at T2 from state 3 to state 4 (p4,V4,T2); process 4 is adiabatic from state 4 back to state 1. w1, w2, w3, w4 are the work done (in calories) in processes 1, 2, 3, 4 and dU2, dU4 are the internal energy changes in processes 2 and 4. [Use R = 2 cal K^-1 mol^-1.] The correct option is: