The elements $X$ and $Y$ undergo a reversible reaction to produce $XY_2$. $X + 2Y \rightleftharpoons XY_2$ $1.0\,\text{mol}$ of $X$ is combined with $1.0\,\text{mol}$ of $Y$ and the mixture is allowed to react until equilibrium is established. Which of the following statements about this reaction are correct?
- A1, 2 and 3
- B2 only
- C3 only
- D2 and 3 only