Answer:
the correct option is D.
Step-by-step explanation:
ionic bond:
ionic bond is a bond where one of the atom donates one or two electron to one or more than one atom for all the atom to attain stability that is octet.
chlorine has 17 electrons so the outer most orbit has 7 electron for it to obtain stability it has to gain one more electron while magnesium has 12 electrons so it has to lose 2 electrons to gain stability so if a magnesium atom loses 2 of its electron to two chlorine atoms botn the chlorine will have 18 electron and magnesium will have 10 electron therefore every atom attaining octet. by this way magnesium forms ionic bond with two chlorine atom to form MgCl2.
so option d must be correct.