Permanently Curled Hair Is Achieved by Applying A(n)____ to the Hair

Permanently curled hair is achieved by applying a(n) ____ to the hair followed by a(n) ____ to reform the disulfide linkages.

A) mild acid, strong base
B) ionic salt, strong acid
C) mild oxidizing agent, mild reducing agent
D) mild reducing agent, mild oxidizing agent
E) strong acid, mild base and cationic salt solution