Which of the following compounds will react with water?

The same product $(A)$ is formed in both of the following reactions:
$1. PhMgBr + CH_3-CN \xrightarrow{H_3O^{+}} (A)$
$2. Ph-COOH \xrightarrow{(1) \text{ excess } CH_3Li, (2) H_3O^{+}} (A)$
Identify product $(A)$.

$A$ carbonyl compound $X$ $(C_8H_8O)$ gives a yellow precipitate with $NaOI$. The hemiacetal of $X$ with methanol/dry $HCl$ is:

Identify the product $A$ in the following reaction:
$\text{Substrate} \xrightarrow{MnO_2} A$
(The substrate is a benzene ring with a $-OH$ group,a $-COOH$ group,and a $-CH(CH_2CH_3)CHO$ group attached to it.)

Which of the following compounds on reaction with ammoniacal silver nitrate solution forms a precipitate of silver?

What product is formed when benzaldehyde reacts with methylamine?