Match the reagent given in column A with its reaction given in column B 

	Column A		Column B
i)	Conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$ /160 -1700C	A)	Dehydrogenation of alcohols
ii)	Alcoholic KOH	B)	Dehalogenation of dihalides
iii)	Cu / 3000C	C)	Dehydration of alcohols
iv)	Zn / alcohol	D)	Dehydrohalogenation of alkyl halides

	(i)	(ii)	(iii)	(iv)
1)	A	B	C	D
2)	C	D	A	B
3)	C	D	B	A
4)	D	A	B	C

i) Conc. ${\mathrm{H}}_2{\mathrm{SO}}_4/160-{170}^0$is dehydration of alcohols
Ex : ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{OH}\underset{160-170°\mathrm{C}}{\overset{\text{ Cons: }{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }}{\mathrm{CH}}_2={\mathrm{CH}}_2+{\mathrm{H}}_2\mathrm{O}$
ii) Alcoholic KOH is used in dehydrohalogenation
Ex : ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{Cl}\stackrel{ \mathrm{alc}.\mathrm{KOH}}{\to }{\mathrm{CH}}_2={\mathrm{CH}}_2+\mathrm{KCl}+{\mathrm{H}}_2\mathrm{O}$
iii) Cu / 300⁰C is used in dehydrogenation
Ex : ${\mathrm{CH}}_3-{\mathrm{CH}}_2\mathrm{OH}\underset{{300}^{\circ }\mathrm{C}}{\overset{\mathrm{CU}}{\to }}{\mathrm{CH}}_3-\mathrm{CHO}+{\mathrm{H}}_2$
iv) Zn / alcohol is used in dehalogenation
Ex : ${\mathrm{CH}}_2\mathrm{Cl}-{\mathrm{CH}}_2\mathrm{Cl}\stackrel{\mathrm{Zn}/ \mathrm{alcohol}}{\to }{\mathrm{CH}}_2={\mathrm{CH}}_2+{\mathrm{ZnCl}}_2$