Given initially

$V_2 = \large\frac{300}{1000}mL$

$P_2 = \large\frac{730}{760}atm$

$T_2 = 300K$

At STP $V_1 = ?$

$P_1 = 1 atm$

$T_1 = 273K$

We use

$\;\;\;\large\frac{P_2V_2}{T_2} = \large\frac{P_1V_1}{T_1}$

$V_1$ = 0.2622 litre

Volume (V) at STP = 262.2 mL

Hence answer is (C)