Maximum enol content is in

Compound $A$ was prepared by oxidation of compound $B$ with alkaline $KMnO_4$. Compound $A$ on reduction with lithium aluminium hydride $(LiAlH_4)$ gets converted back to compound $B$. When compound $A$ is heated with compound $B$ in the presence of $H_2SO_4$,it produces a fruity smell of compound $C$. To which family do the compounds $A$,$B$,and $C$ belong?

Which of the following reactions produce carboxylic acids?
$(a)$ $MnO_2$ with $CH_3COCH_3$
$(b)$ $Ph-CCl_3 \xrightarrow[(ii) H_2O/H^+]{(i) aq. NaOH} PhCOOH$
$(c)$ $C_2H_5Br \xrightarrow[(iii) H_2O/H^+]{(i) Mg, (ii) CO_2} C_2H_5COOH$
$(d)$ $CH_3CH=CHCH_3 \xrightarrow[\Delta]{K_2Cr_2O_7/H_2SO_4} 2CH_3COOH$

Write chemical reactions to affect the following transformations:
$(i)$ Butan$-1-$ol to butanoic acid
$(ii)$ Benzyl alcohol to phenylethanoic acid
$(iii)$ $3-$Nitrobromobenzene to $3-$nitrobenzoic acid
$(iv)$ $4-$Methylacetophenone to benzene$-1,4-$dicarboxylic acid
$(v)$ Cyclohexene to hexane$-1,6-$dioic acid
$(vi)$ Butanal to butanoic acid.

Match Column-$I$ with Column-$II$ :
| Column-$I$ | Column-$II$ |
| :--- | :--- |
| $(A)$ Cyclopentanone + $2,4-$$DNP$ $\xrightarrow{\text{mild } H^+}$ Cyclopentanone$-2,4-$$DNP$ derivative | $(P)$ Electrophilic substitution |
| $(B)$ $4-$phenyl$-2-$methylbutan$-2-$ol $\xrightarrow{\text{Conc. } H_2SO_4}$ $1,1-$dimethyl$-1,2,3,4-$tetrahydronaphthalene | $(Q)$ Nucleophilic substitution |
| $(C)$ $4-$chlorocyclohexanethiol $\xrightarrow{\text{Base}}$ $7-$thiabicyclo[$2.2$.$1$]heptane | $(R)$ Nucleophilic addition |

Ethanol on reaction with acetic anhydride gives