Three compounds, X, Y and Z, are shown here. $X$: $\text{C}_2\text{H}_5\text{COCH}_3$, $Y$: $\text{C}_2\text{H}_5\text{CHO}$, $Z$: $\text{CH}_3\text{CO}_2\text{H}$. Which of the following statements about X, Y and Z are correct?
- A1, 2 and 3
- B1 and 2 only
- C2 and 3 only
- D1 only