From ideal gas equation,
$pV = nRT$
$\Rightarrow V=\frac{n R T}{p}$
For $n =1 mole$
$V=\frac{R T}{p}$
$\Rightarrow V \propto T$
$\therefore $ The molar volume of $CO _{2}$ at
a)NTP
$V=\frac{0.0821 \times 273}{1}=22.4\, L$
b) $0^{\circ} C$ and $2.0\, atm$
$V=\frac{0.0821 \times 273}{2.0}=11.2\, L$
c) $127^{\circ} C$ and $1\, atm$
$V=\frac{0.0821 \times 400}{1}=32.84\, L$
d) $273^{\circ} C$ and $2\, atm$
$V=\frac{0.0821 \times 546}{2}=22.4\, L$
Therefore the molar volume of $CO _{2}$ is maximum at
$127^{\circ} C$ and $1\, atm$.