What is the primary role of a neutralizer in chemical hair processes?

The primary role of a neutralizer in chemical hair processes is to lock in curls. When a perm is applied, the hair's disulfide bonds are broken down, allowing it to be reshaped into curls. After this reshaping process, a neutralizer is used to re-bond the disulfide bonds in their new position. This is crucial because it helps to "set" the curls, ensuring that they maintain their shape and structure after the processing is complete. Without the neutralizer, the curls would not hold and the hair could revert to its original straight form.

The other choices do not accurately represent the function of a neutralizer in this context. Moisturizing the hair, while important in overall hair care, is not the primary purpose of a neutralizer, which focuses specifically on chemical bond reconstruction. Similarly, relaxing the hair refers to a different type of chemical process that aims to straighten and reduce curl, contrasting with the curling action that a neutralizer supports. Removing build-up pertains to cleaning solutions and treatments to clear product residue from hair, which is unrelated to the neutralization of chemical treatments.