Final answer:
c) average
Hair that has normal moisture absorption is said to have average porosity, which is ideal for maintaining healthy hair as it balances the ability to absorb and retain moisture.
Step-by-step explanation:
Hair with normal ability to absorb moisture is said to have average porosity. Porosity refers to the hair's ability to absorb and retain moisture, and can be categorized as low, normal, or high. When hair exhibits normal porosity, it can properly absorb and maintain moisture without difficulty, meaning it is neither too resistant nor too absorbent. This characteristic is essential for healthy hair, as it ensures that the hair can adequately receive moisture from hair care products and the environment, contributing to its strength and elasticity.