$A \xrightarrow[\begin{smallmatrix} (ii) CN^{-} \\ (iii) H_{2}O/H^{+} \end{smallmatrix}]{(1) Cl_{2}, \Delta }$ $4-$Bromophenyl acetic acid.
In the above reaction '$A$' is ....

$CH_3-(CH_2)_3-OH$ $\xrightarrow[Et_3N]{CH_3-SO_2-Cl} (A)$ $\xrightarrow{K^{14}CN} (B)$ $\xrightarrow{H_3O^{\oplus}} (C)$
Product $(C)$ is

Consider the following reactions. From these reactions,which reaction will give carboxylic acid as a major product?
$(A)$ $R-C \equiv N \xrightarrow[(i) H^{+}/H_2O]{\text{mild condition}} R-CONH_2$
$(B)$ $R-MgX \xrightarrow[(ii) H_3O^{+}]{\text{(i) } CO_2} R-COOH$
$(C)$ $R-C \equiv N \xrightarrow[(ii) H_3O^{+}]{\text{(i) } SnCl_2/HCl} R-CHO$
$(D)$ $R-CH_2-OH \xrightarrow{PCC} R-CHO$
$(E)$ $\text{Benzoyl chloride} \xrightarrow[(ii) Br_2/H_2O]{\text{(i) } H_2/Pd-BaSO_4} \text{Benzoic acid}$
Choose the correct answer from the options given below:

The major product in the following reaction is:

The major product formed when $1, 1, 1-$trichloropropane is treated with aqueous potassium hydroxide is:

The compound formed as a result of potassium permanganate oxidation of ethylbenzene is