Which product is commonly used to prepare hair before applying a relaxer?

The correct choice is a protective barrier cream, which is essential for preparing hair prior to applying a relaxer. This type of cream is used to safeguard the scalp and hairline from the harsh chemicals present in relaxers. It creates a protective layer that prevents burns and irritation, ensuring a safer application of the chemical product.

Using a protective barrier is crucial because relaxers can be very potent, and direct contact with sensitive areas like the scalp can lead to discomfort and damage. This preparation step is a standard practice in chemical texturizing to ensure client safety and comfort.

In contrast, other options like leave-in conditioner, shampoo with sulfates, and hair gel do not serve as effective protective measures. While leave-in conditioners can help in moisturizing and preparing hair texture, they do not specifically form a protective barrier from the relaxer. Sulfates in shampoos can strip away natural oils and weaken hair, which is not ideal before applying strong chemicals. Hair gel is typically used for styling rather than for pre-treatment in chemical processes.