The relation between volume and temperature is direct, this is the higher the temperature the higher larger the volume.
Therefore, if you want that your gas occupies a larger volumen, you should increase the temperature, assuming other conditions (pressure and number of moles) remain unchanged.
The new temperature may be calculated using the proportion:
V1 / T1 = V2 / T2
=> T2 = V2 * T1 / V1
T1 and T2 are in absolute degrees, so T1 = - 73 + 273.15 = 200.15 K
=> T2 = 360 ml * 200.15 K / 210 ml = 343
Answer: the temperature should be increased to 343 K
