The figure shows the \((P\text-V)\) diagram of an ideal gas undergoing a change of state from \(A\) to \(B.\) Four different paths \(\mathrm{I, II, III}\) and \(\mathrm{IV},\) as shown in the figure, may lead to the same change of state.
                  

(a) The change in internal energy is the same in cases \(\mathrm{IV}\) and \(\mathrm{III}\) but not in cases \(\mathrm{I}\) and \(\mathrm{II}.\)
(b) The change in internal energy is the same in all four cases.
(c) The work done is maximum in case \(\mathrm{I}.\)
(d) The work done is minimum in case \(\mathrm{II}.\)


Which of the following options contains only correct statements?

1. (b), (c) and (d) only 2. (a) and (d) only
3. (b) and (c) only 4. (a), (c) and (d) only