Answer:
The correct option is B.
Explanation:
Ionic bond are usually formed between a metal and a non metal. The metal usually acts as the electron donor while the non metal acts as the electron acceptor, that is, the metal give away electrons while the non metal accept the electrons. In the options given in this question, it is only the pairs in option B, that is qualify for ionic bond, this is because it consist of a metal and a non metal.
