d
$\mathrm{PV}=\mathrm{nRT}$
$\mathrm{V}=\left(\frac{\mathrm{nR}}{\mathrm{P}}\right)_{\mathrm{T}}$
$\text { Slope }=\frac{\mathrm{nR}}{\mathrm{P}}$
$\text { Slope } \propto \frac{1}{\mathrm{P}}$
$(\text { Slope })_2>(\text { Slope })_1$
$\mathrm{P}_2<\mathrm{P}_1$