$p$-cresol reacts with chloroform in an alkaline medium to give compound $A$,which adds hydrogen cyanide to form compound $B$. The latter,on acidic hydrolysis,gives a chiral carboxylic acid. The structure of the carboxylic acid is:

The aldehydes which will not form a single Grignard product with one equivalent of Grignard reagent are:
$(a)$ Benzaldehyde
$(b)$ $4$-Formylbenzoic acid
$(c)$ $4$-Methoxybenzaldehyde
$(d)$ $4$-(Hydroxymethyl)benzaldehyde

When liquid $A$ is treated with a freshly prepared ammoniacal silver nitrate solution,it gives a bright silver mirror. The liquid forms a white crystalline solid on treatment with sodium hydrogensulphite. Liquid $B$ also forms a white crystalline solid with sodium hydrogensulphite but it does not give a test with ammoniacal silver nitrate. Which of the two liquids is an aldehyde? Write the chemical equations of these reactions also.

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:

Which of the following reagents should be used to carry out the above conversion $:-$
(Image shows the reduction of a ketone group to a secondary alcohol in the presence of an ester group)

Which among the following has the lowest boiling point?