The correct option is B H2O
Amphiprotic Species:
Species which can accept H+ as well as donate H+.
As per Bronsted-Lowry’s theory, species which can act as an acid as well as a base.
Water is amphiprotic in the following reactions,
HCl(aq)+H2O(aq)⇌H3O+(aq)+Cl−(aq), here H2O(aq) is accepting H+
NH3(aq)+H2O(aq)⇌NH+4(aq)+OH−(aq), here H2O(aq) is giving H+
Therefore water is amphiprotic.