d.
Because a complete ionic equation wants you to show everything participating in the reaction. Even if some are spectator ions that do not affect the final equation you still must include them and therefore c. could not be the answer.
Answer: Option (d) is the correct answer.
Explanation:
An ion is a specie that contains either a positive or a negative charge.
For example, [tex]Na^{+}[/tex], [tex]Ag^{+}[/tex], [tex]Cl^{-}[/tex], [tex]NO^{-}_{3}[/tex], etc are all ions.
Therefore, an ionic equation is defined as an equation that contains participating dissolved species in the form of ions.
For example, [tex]Ag^{+} + NO^{-}_{3} + Na^{+} + Cl^{-} \rightarrow AgCl(s) + Na^{+} + NO^{-}_{3}[/tex]
Here, only AgCl is the precipitate as it is insoluble but rest of the species are ions as they have dissolved.
Thus, we can conclude that a complete ionic equation an equation showing all dissolved compounds as ions.
