The key step in Cannizzaro's reaction is the intermolecular shift of

$(A)$ and $(B)$ in the following reaction sequence are:
$RR'C=O$ $\xrightarrow{HCN} (A)$ $\xrightarrow{B} RR'C(OH)CH_2NH_2$

Identify the structure of $B$ in the following reaction sequence:
$2,6-\text{dimethylcyclohexane-1,4-dione} + \text{ethane-1,2-diol}$ $\xrightarrow{H^+} A$ $\xrightarrow[2. H_3O^+]{1. LiAlH_4} B$

Compound $(A)$ with molecular formula $C_{11}H_8O$ does not undergo self-aldol condensation. Upon ozonolysis,it yields $Ph-CHO$ and $2B$,where $B$ on oxidation with $Ag^{+}$ gives oxalic acid. Identify compound $(A)$.

Identify the products $(A)$ and $(C)$ in the following reaction sequence:
$Cyclopentyl-^{14}CN + CH_3MgBr$ $\xrightarrow{H_3O^\oplus} (A)$ $\xrightarrow{NaOI} (B) + (C)$

The reactants $(A)$ and $(B)$ are: