A pre-weighed vessel was filled with oxygen at `NTP` weighted. It was the evacuated, filled with `SO_(2)` at the same temperature and pressure, and again weighted. The weight of oxygen will be
A. The same as that of `SO_(2)`
B. `(1)/(2)` that of `SO_(2)`
C. Twice that of `SO_(2)`
D. One-fourth that of `SO_(2)`