In the ionization of nitric acid shown below, what role does water play?
HNO3+H2O→NO3−+H3O+
a) Water is a spectator species because its composition remains unchanged during the reaction.
b) Water acts as an acid because it donates a proton to NO3−.
c) Water acts as a base because it accepts a proton from HNO3.
d) Water acts as both an acid and a base simultaneously because it is amphoteric and auto-ionizes.