Which of the Following in the Reaction $\mathrm { HCl } + \mathrm { H } _ { 2 } \mathrm { Of } \quad \mathrm { H } _ { 3 } \mathrm { O } ^ { + } + \mathrm { Cl } ^ { - }$

Multiple Choice

Which of the following in the reaction $\mathrm { HCl } + \mathrm { H } _ { 2 } \mathrm { Of } \quad \mathrm { H } _ { 3 } \mathrm { O } ^ { + } + \mathrm { Cl } ^ { - }$ constitute a conjugate acid-base pair?

A) $\mathrm { HCl } \text { and } \mathrm { H } _ { 2 } \mathrm { O }$
B) $\mathrm { H } _ { 2 } \mathrm { O } \text { and } \mathrm { Cl } ^ { - }$
C) $\mathrm { HCl } \text { and } \mathrm { H } _ { 3 } \mathrm { O } ^ { + }$
D) $\mathrm { H } _ { 3 } \mathrm { O } ^ { + } \text {and } \mathrm { Cl } ^ { - }$
E) $\mathrm { H } _ { 2 } \mathrm { O } \text { and } \mathrm { H } _ { 3 } \mathrm { O } ^ { + }$