The expansion of an ideal gas of mass m at a constant pressure P is given by the straight line D. Then the expansion of the same ideal gas of mass 2m at a pressure P/2 is given by the straight line : 

A

\(PV \propto MT\) \Rightarrow \(\frac{V}{T} \propto \frac{M}{P}\)

Here (M/P) represents the slope of curve drawn on volume and temperature axis.

For the first condition slope (M/P) graph is D (give in the problem)

For the second condition slope : \(\frac{2M}{P/2} = 4(\frac{M}{P})\)

i.e. slope becomes four times so graph A is correct in this condition.