The conjugate acid of H 2 O is ________.

The conjugate acid of a base is formed by adding a proton (H+) to the base. HS^(-) becomes H2S when a proton is added, which is represented as HS^(-) + H^+ -> H2S. The correct representation of H2S in the given options, considering the proton is added, is HS^+ (option C).

The conjugate acid of H 2 O is ________.

The conjugate acid of a base is formed by adding a proton (H+) to the base. HS^(-) becomes H2S when a proton is added, which is represented as HS^(-) + H^+ -> H2S. The correct representation of H2S in the given options, considering the proton is added, is HS^+ (option C).