Which reagent turns pink in the presence of an aldehyde?

The correct order of the rate of reaction with $PhMgBr$ is:

Propyne was subjected to a reaction with $HgSO_4/dil. H_2SO_4$,which resulted in a product $P$. The product $P$ was heated with $Ba(OH)_2$ to give the product $Q$. The molecular formula of the product $Q$ is

The structure of $(R)$ is:

When a nucleophile encounters a ketone,the site of attack is

Reduction of $>C=O$ to $CH_2$ can be carried out with: