Final answer:
In the nomenclature of ionic compounds, the cation is written first followed by the anion.option (A).
Step-by-step explanation:
When naming an ionic compound, the cation is always written first, followed by the anion. This aligns with the conventional rules for naming ionic compounds, which dictate listing the positively charged ion (cation) before the negatively charged ion (anion).
For instance, in the compound formed between sodium (Na+) and chloride (Cl-), sodium is the cation and chloride is the anion, hence the compound is named sodium chloride and written as NaCl. It is important to note that the formula represents the simplest whole-number ratio of ions required to achieve a neutral overall charge, with no individual charges shown in the formula itself.