Assertion: Under similar conditions of temperature and pressure,`O_(2)` diffuses `1.4` times faster than `SO_(2)`.
Reason: Density of `SO_(2)` is `1.4` times greater than that of `O_(2)`.
A. If both (`A`) and (`R`) are correct and (`R`) is the correct explanation of (`A`).
B. If both (`A`) and (`R`) are correct, but (`R`) is not the correct explanation of (`A`).
C. If (`A`) is correct, but (`R`) is incorrect.
D. If (`A`) is incorrect, but (`R`) is correct.