Which of the following is least likely to be a benefit of a leave-in conditioner?

A leave-in conditioner is primarily designed to provide ongoing moisture, nourishment, and management for the hair after it has been washed. One of its core benefits is protection from heat styling, as many leave-in conditioners contain ingredients that can form a protective barrier on the hair, helping to reduce damage caused by heat from styling tools.

Additionally, leave-in conditioners are effective at enhancing shine and smoothness because they often contain silicones or light oils that help to seal the hair cuticle, resulting in a polished and shiny appearance. They are also formulated to assist in detangling, making it easier to comb through hair without causing breakage or damage.

Deep cleansing of hair, however, is not a function of leave-in conditioners. This process is typically accomplished through shampoos specifically designed to remove buildup, dirt, and oils from the scalp and hair. Leave-in conditioners serve a different purpose, focusing on conditioning rather than cleansing. Therefore, deep hair cleansing is the least likely benefit associated with the use of a leave-in conditioner.