The Tischenko reaction yields an ester in the presence of which catalyst?

Nucleophilic addition reaction will be most favoured in:

In the given reaction,the number of chiral carbon$(s)$ in product $A$ is .......
(Where $Et$ is $-C_2H_5$)

What will be $X$ and $Y$ in the following reaction?

The active ion in Tollen's reagent is

Given below are two statements:
Statement $I$: $2, 6$-diethylcyclohexanone and $6$-methyl-$2$-$n$-propylcyclohexanone are metamers.
Statement $II$: $2, 2, 6, 6$-tetramethylcyclohexanone exhibits keto-enol tautomerism.