Assertion : Lyophilic colloids such as starch, gelatin etc, act as protective colloids.
Reason : Protective power of lyophilic coloids is expressed in terms of gold number.
A. If both assertion and reason are correct and reason is correct explanation for assertion.
B. If both assertion and reason are correct but reason is not correct explanation for assertion.
C. If assertion is correct but reason is incorrect.
D. If assertion and reason both are incorrect.