Which of the following substances will give the silver mirror test?

Given below are two statements: Consider the following reaction: $R_2C=O + H_2O \rightleftharpoons R_2C(OH)_2$.
Statement $I$: In the case of formaldehyde $(HCHO)$,$K_{eq}$ is about $2280$,due to small substituents,hydration is faster.
Statement $II$: In the case of trichloroacetaldehyde $(CCl_3CHO)$,$K_{eq}$ is about $2000$ due to the $-I$ effect of $-Cl$ atoms.
In the light of the above statements,choose the correct answer from the options given below:

The major product $X$ formed in the following reaction is:

Which of the following compounds is highly reactive towards $HCN$?

Which reactant will give the following alcohol on reaction with one mole of phenyl magnesium bromide $(PhMgBr)$ followed by acidic hydrolysis?

The correct order of decreasing value of $K_{eq.}$ for the addition of $HCN$ to the following carbonyl compounds is:

Reactant	$K_{eq.}$
$PhCHO$	$a$
$CH_3CH_2COCH_3$	$b$
$PhCOCH_3$	$c$
$CH_3CHO$	$d$