Answer: Option (a) is the strong acid.
Explanation:
Hydrochloric acid is a strong acid and when it is added to water then the following reaction takes place.
[tex]HCl + H_{2}O \rightarrow H_{3}O^{+} + Cl^{-}[/tex]
where, [tex]H_{3}O^{+}[/tex] is a conjugate acid and [tex]Cl^{-}[/tex] is a conjugate base.
Therefore, when we add HCl into water then it dissociates completely into hydronium ion and chlorine ion.
Thus, we can conclude that a strong acid is disassociated completely, producing more conjugate base.