The correct answer is C. A positive calcium ion and a negative oxygen ion
Step-by-step explanation:
In chemistry, an ionic bond occurs as ions with opposite charges attract each other and then create a bond due to the transference of electrons from one atom to other. This means, this type of bond occurs between an atom that is positively charged and one that is negatively charged, therefore, the two particles that can form an ionic bond are "A positive calcium ion and a negative oxygen ion" because these two have opposite charges (one is positively charged and one is negatively charged) and therefore electrons can be transferred from one atom to another forming an ionic bond.