Starting with the same initial conditions, an ideal gas expands from volume V1 to V2 in three different ways, the work done by the gas is W1 if the process is purely isothermal, W2 if purely isobaric and W3 if purely adiabatic, then (JEE 2000)
a. W2>W1>W3
b. W2>W3>W1
c. W1>W2>W3
d. W1>W3>W2