Explanation

Answer: 

C: Heating of Mercuric oxide powder: The heating of Mercuric oxide powder is a permanent change. We cannot get powder by revere reaction so it is a chemical change

Sublimation of Iodine: It is a physical change

Heating a platinum wire in a Bunsen flame: Platinum is a noble gas that cannot change its physical appearance after heating. So it is not a chemical change

Evaporation of Alcohol: It is a physical change. The liquid is changed into gas