<em>The possible choice is a </em><em><u>non-metal that lacks an octet configuration</u></em><em>.</em>
<h3><u>Explanation</u>;</h3>
<em><u>Ionic bond is a type of bond that is formed between a metal and a non metal. </u></em>This type of<em><u> bond occurs as a result of transfer of electrons where an atom of a metal looses electrons and that of a non metal gains electrons.</u></em> Consequently, the atoms involved attain a stable configuration, where one becomes a cation and the other becomes an anion.
In this case,<em><u> Sodium and a non metal that does not have an octet configuration will form an ionic bond because sodium is a metal that requires to loose one electron to form a stable configuration,</u></em> while a non metal would require to gain electron(s) to attain a stable configuration.
