Final answer:
Melanocytes (option a) in the stratum basale of the epidermis produce melanin, which is transferred to keratinocytes and helps to protect the skin from UV radiation.
Step-by-step explanation:
The tiny grains of pigment deposited in cells that provide skin with color are melanocytes. Melanocytes are found in the stratum basale of the epidermis and produce the pigment melanin. This melanin is then transferred to keratinocytes in the epidermis, which plays a crucial role in protecting the skin against UV radiation. Melanocytes produce and store melanin in organelles called melanosomes.
When the melanosomes are filled with melanin, they are transported to the keratinocytes, which absorb UV light and prevent it from penetrating deeper into the skin, thereby reducing the risk of damage. The amount of melanin in the skin varies depending on heredity and exposure to sunlight.