reversible thermodynamic cycle

Question

A reversible thermodynamic cycle containing only three processes and producing work is to be constructed. The constraints are                                                                                                                                            

1. There must be one isothermal process,
2. There must be one isentropic process,
3. The maximum and minimum cycle pressures and the clearance volume are fixed,
4. Polytropic processes are not allowed.

      Then the number of possible cycles are

      (a) 1                                                                    (b) 2

      (c) 3                                                                    (d) 4