Inside a car engine, the non-metal element $X$ produces a polluting oxide, $Y$. Oxide $Y$ may then be oxidised further to $Z$. Two students put forward these claims. Student P: The molecule of $Y$ has lone pairs of electrons. Student Q: From $Y$ to $Z$, the oxidation number of $X$ rises by $1$. $X$ could be carbon or nitrogen or sulfur. Which student could be right if $X$ was any one of these elements?
- AP only
- BQ only
- Cboth P and Q
- Dneither P nor Q