Canities is the result of what change in the hair?

Canities refers to the graying of hair, which occurs due to a gradual decline in melanin production within the hair follicle. Melanin is the pigment responsible for giving hair its color. As people age, the melanocytes (the cells that produce melanin) become less active, leading to less pigment being added to the hair strands. This results in hair that progressively loses its color and appears gray or white.

The correct choice reflects the biological process that leads to canities. The gradual decrease in melanin is a natural part of the aging process and can also be influenced by genetic factors. In contrast, an increase in melanin would lead to darker hair, while keratin, the protein that makes up the structure of hair, does not affect hair color. A sudden change in hair texture is unrelated to the pigmentation process that defines canities.