The answer would be:
No Combustion
If you'd like to know why:
Your clue to this is the word "combustion." Combustion is a chemical reaction and chemical properties can only be observed by inducing or creating a chemical reaction. Flammability is a chemical property and this is what is tested in terms of combustion. This is because the reactants in combustion create a new product. The other given properties are all physical properties.
