Final answer:
The correct combination for the cobalt cation, Co²⁺, from the list is CoF₂ as it results in an electrically neutral compound and represents the cobalt(II) cation in an ionic bond with fluoride anions.
Step-by-step explanation:
When dealing with the cation cobalt in the form of Co²⁺, the suitable combination from the provided list is CoF₂. This option precisely designates that cobalt is in a +2 oxidation state, denoted as cobalt(II) cation. In the compound CoF₂, cobalt is intricately bonded with two fluoride anions, each carrying a -1 charge. This arrangement results in the formation of an ionic compound, where the cation interacts with anions to achieve an overall neutral charge. Therefore, the accurate selection is option 'c' CoF₂, aligning with the characteristics of cobalt in the +2 oxidation state.