Which of the following products is formed when benzaldehyde is treated with $CH_3MgBr$ and the addition product so obtained is subjected to acid hydrolysis?

Addition of alcohols to aldehydes in the presence of anhydrous acids yields:

Which of the following compounds undergoes aldol condensation?

The reactant is $3$-methylpentanal. The reaction with $NaCN$ followed by $H_2SO_4$ (cyanohydrin formation) is shown below:
$CH_3CH_2CH(CH_3)CH_2CHO \xrightarrow{NaCN/H^+} CH_3CH_2CH(CH_3)CH_2CH(OH)CN$
Products of the reaction are:

$CH_3CH=CHCHO$ $\xrightarrow[\text{Aldol condensation}]{OH^{-}}$ $\xrightarrow{\Delta} A$; Product $A$ is

Give the conversion of the following:
$(i)$ Benzoic acid from Bromobenzene
(ii) $2$-methylbutan-$2$-ol from Propenone