Which of the following is a nucleophilic addition reaction?

Statement $I$: Aldehyde on reaction with $HCN$ gives Cyanohydrin.
Statement $II$: Cyanohydrin is a compound which consists of hydroxy and cyano groups on the same carbon.
Choose the correct answer from the following with reference to above statements.

Formalin is the commercial name of

In the following table,Column-$I$ shows the structure of a compound,Column-$II$ shows its $IUPAC$ name,and Column-$III$ shows its common name. Match the $IUPAC$ name and common name for each structure given in Column-$I$.
| Column-$I$ (Structure) | Column-$II$ ($IUPAC$ name) | Column-$III$ (Common name) |
| :--- | :--- | :--- |
| $(A)$ $C_6H_4(CHO)_2$ (ortho) | $(i)$ Benzophenone | $(p)$ Acrolein |
| $(B)$ $(CH_3)_2C=CHCOCH_3$ | $(ii)$ Benzene$-1,2-$dicarbaldehyde | $(q)$ Diphenyl ketone |
| $(C)$ $CH_2=CH-CHO$ | $(iii)$ Prop$-2-$enal | $(r)$ Phthaldehyde |
| $(D)$ $(C_6H_5)_2CO$ | $(iv)$ $4-$methylpent$-3-$en$-2-$one | $(s)$ Mesityl oxide |

What is the product of the following reaction?

$A$ reaction of benzonitrile with one equivalent of $CH_{3}MgBr$ followed by hydrolysis produces a yellow liquid $P$. The compound $P$ will give a positive result for which of the following tests?