Which of the following best explains how chemical hair relaxers work?

• A. They coat the hair with silicone to make it appear straighter.
• B. They dissolve the hair cuticle, making hair softer and straighter.
• C. They break and reform the disulfide bonds in keratin, altering the hair's structure.
• D. They add moisture to the hair, causing it to relax and straighten.

Answer: (C)

Verified step by step guidance

1. Understand that hair structure is primarily determined by keratin proteins, which contain disulfide bonds (S-S bonds) that maintain the hair's shape and strength.
2. Recognize that chemical hair relaxers work by targeting these disulfide bonds, breaking them temporarily to allow the hair to be reshaped.
3. Know that after breaking the disulfide bonds, the relaxer allows the hair to be straightened, and then the bonds are reformed in the new, straighter configuration.
4. Note that this process changes the internal chemical structure of the hair rather than just coating or moisturizing it.
5. Conclude that the best explanation is that chemical hair relaxers break and reform the disulfide bonds in keratin, altering the hair's structure.