What is the primary function of hair conditioner?

The primary function of hair conditioner is to restore moisture and softness to the hair. Conditioners are formulated with ingredients that help to replenish hydration, improve the hair's texture and manageability, and reduce frizz. When hair is washed with shampoo, it can lose its natural oils, making it more prone to dryness and damage. Conditioners work by coating the hair strands, which helps to lock in moisture, making the hair feel softer and healthier. Additionally, conditioners often contain nourishing ingredients that can help to repair damage and enhance the overall appearance of the hair.

While cleansing hair is the role of shampoo, heat protection is typically provided by specialized products rather than conditioners alone. Similarly, while some conditioners may slightly enhance volume as a side effect, this is not their primary function. The main focus of conditioner is indeed to restore moisture and improve the softness of the hair, making option C the correct choice.