Which of the following has highly acidic hydrogen?

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 |

$CH_3CH_2COOH$ $\xrightarrow{P_2O_5}$ $X$ $\xrightarrow{H_2O}$ $Y$ $\xrightarrow{SOCl_2}$ $Z$
Identify $X$,$Y$ and $Z$.

Match the compounds possessing carbonyl carbon in Column-$I$ with their formulas in Column-$II$ and examples in Column-$III$:

Column-$I$ (Name)	Column-$II$ (Formula)	Column-$III$ (Example)
$(A)$ Ketone	$(i)$ $R-CO-OH$	$(p)$ $CH_3CHO$
$(B)$ Carboxylic acid	$(ii)$ $R-CO-H$	$(q)$ $CH_3COOH$
$(C)$ Amide	$(iii)$ $R-CO-R'$	$(r)$ $CH_3CONH_2$
$(D)$ Aldehyde	$(iv)$ $R-CO-NH_2$	$(s)$ $CH_3COC_2H_5$

The correct order of acid strength of the following carboxylic acids is $-$

Which of the following pairs of compounds can be differentiated by $NaHCO_3$ as well as by $NaOH$?