Identify the reactions which give aniline as the major product....

Let us analyze each reaction to determine the major product:

Reaction A: Benzonitrile ($C_6H_5CN$) is reduced by $LiAlH_4$, a strong reducing agent, to form benzylamine.
$C_6H_5CN \xrightarrow{LiAlH_4} C_6H_5CH_2NH_2$

Reaction B: Benzamide ($C_6H_5CONH_2$) undergoes Hoffmann bromamide degradation in the presence of $KOH$ and $Br_2$ to form aniline.
$C_6H_5CONH_2 \xrightarrow{KOH, Br_2} C_6H_5NH_2$

Reaction C: Nitrobenzene ($C_6H_5NO_2$) is not reduced to aniline by $NaBH_4$. $NaBH_4$ is a mild reducing agent and generally does not reduce the $-NO_2$ group.

Reaction D: Acetanilide ($C_6H_5NHCOCH_3$) undergoes acid-catalyzed hydrolysis upon heating to yield aniline and acetic acid.
$C_6H_5NHCOCH_3 \xrightarrow{HCl, H_2O, \Delta} C_6H_5NH_2 + CH_3COOH$

Thus, reactions B and D give aniline as the major product.

Answer: B and D only