What are the common types of perms?

B is the correct choice because alkaline, acid, and exothermic perms represent the different chemical methods used to create curls or waves in hair through the perming process. Alkaline perms typically use a higher pH and are suitable for resistant hair types, providing firm curls. Acid perms have a lower pH, making them gentler on the hair, ideal for finer or damaged hair, and they produce softer, more natural-looking waves. Exothermic perms generate heat through a chemical reaction, allowing the perming process to occur more quickly and often resulting in long-lasting curls.

The other options do not correctly categorize the common types of perms based on how they chemically alter the hair structure. Wavy, curly, and straight perms describe potential outcomes rather than distinct techniques. Traditional, modern, and hybrid perms are also not standard classifications within perming techniques but rather subjective terms that may vary by stylist. Lastly, seasonal, permanent, and temporary perms emphasize the duration rather than the chemical process involved. Thus, the second choice accurately identifies the main types of perms used in professional hairstyling.