Weak acid. d. weak base. an amphoteric species is one that reacts as a. acid only. b. base only. a(n) c. acid or base. none of the above

 The nature of an amphoteric substance is amphoprotic; it has ability to donate proton or gain proton. So the amphotric substances are those which can react as both acid or base in a reaction. Many oxides of metals when subjected to a reaction mixture can acts as both an acid or either a base, they are called amphoteric oxides. some of the examples of these amphoteric oxide is zinc oxide and lead oxide.

Hence, the correct option here is (c )