What is one of the key functions of a conditioner?

One of the key functions of a conditioner is to add moisture and improve the texture of the hair. Conditioners are formulated with ingredients that hydrate and nourish the hair, helping to restore its natural moisture balance. This hydration helps soften the hair, making it more manageable and reducing frizz. Additionally, conditioners can smooth the cuticle layer of the hair, leading to improved shine and easier styling.

The other options do not reflect the primary purpose of conditioners. For instance, removing color from hair is typically a function of hair dyes or color removers, while repelling water is not a desirable characteristic for hair care products, as hair generally needs to absorb moisture. Increasing hair volume is usually addressed by volumizing products, rather than conditioners, which focus on moisture and texture.