The major product formed in the following reaction sequence is $CH_3-CH=CH_2$ $\xrightarrow[\substack{(iii) \ CH_3-CH_2-CHO \\ (iv) \ CrO_3}]{\substack{(i) \ HBr, \text{ peroxide} \\ (ii) \ Mg}}$

Identify the product $A$ in the following reaction:

When ethanal $(CH_3CHO)$ and propanal $(CH_3CH_2CHO)$ undergo cross-aldol condensation with dilute $NaOH$, the pair of products obtained by cross-condensation reaction is:

Given below are two statements :
Statement $I :$ The nucleophilic addition of sodium hydrogen sulphite to an aldehyde or a ketone involves proton transfer to form a stable ion.
Statement $II :$ The nucleophilic addition of hydrogen cyanide to an aldehyde or a ketone yields amine as final product.
In the light of the above statements,choose the most appropriate answer from the options given below :

Benzene on reaction with acetyl chloride in the presence of anhydrous $AlCl_3$ gave the product $P$. The product $P$ on reaction with methyl magnesium bromide followed by treatment with water furnished the product $Q$. The molecular formula of $Q$ is

$C_6H_5CHO + C_6H_5COCH_3 \xrightarrow[293 \ K]{OH^{-}}$ product of reaction is . . . . . . .