Answer: Option (c) is the correct answer.
Explanation:
Properties which does not affect the chemical composition of a substance are known as physical properties.
For example, mass, melting point, boiling point etc are all physical properties.
When there is change in pH of milk then it means chemical composition of substance has changed.
Also, when milk is spoiled then chemical change has occurred and when milk curdles on mixing vinegar then also chemical composition has changed.
Thus, we can conclude that out of given options milk boils at about 212°F (100°C) represents physical property of milk.