Solution:
Concept- when naming the compound, the cation is first named then anion. In Mercury (II) chloride (mercuric chloride), mercury in a +2 oxidation state is present as a cation. And chlorine in the -2 oxidation state is present as an anion.To neutralize the charge, two chloride ions must be present in one molecule. Therefore, the molecular formula of Mercury (II) chloride is
Hence, the correct answer is option 2.