The correct option is D 44.8 litre
At 273 K and 1 atm pressure, gas occupies 22.4 litres molar volume. In the given question, pressure = 1 atm, n = 1 mol and temperature =273oC=546K. Thus, at 546 K and 1 atm pressure, an ideal gas would occupy 44.8 litres of molar volume, as volume is directly proportional to temperature, at constant pressure. When the temperature doubles, the volume also doubles.