Which of the following compounds gives a ketone with a Grignard reagent?

Which of the following reagents/reactions will convert $A$ to $B$?

In the reaction,$C_6H_5CN$ $\xrightarrow[(ii) H_3O^+]{(i) SnCl_2 + HCl} X$ $\xrightarrow{conc. KOH} Y + Z$,the formation of $X, Y$ and $Z$ are known by:

The reaction shown below is known as:
$C_6H_6 + CO + HCl \xrightarrow{\text{anhyd. } AlCl_3} C_6H_5CHO$

What is the major product obtained when calcium acetate and calcium formate are heated together?

Identify the product in the following reaction: $Pent-3-enenitrile \xrightarrow[H_3O^+]{AlH(i-Bu)_2} \text{Product}$