Within a car engine, the non-metal element X produces the pollutant oxide Y. Y then undergoes further oxidation to Z in the atmosphere. During this extra oxidation, $1$ mol of Y reacts with $\frac{1}{2}$ mol of gaseous oxygen. Which element could X be?
- A1, 2 and 3
- B1 and 2 only
- C2 and 3 only
- D1 only