Final answer:
The two basic factors interacting to produce skin color are the presence of carotene and melanin (Option B).
Step-by-step explanation:
The two basic factors interacting to produce skin color are the presence of carotene and melanin (Option B). Skin pigmentation is a complex trait mainly influenced by melanin, which is produced by melanocytes in the stratum basale of the epidermis and then transferred into keratinocytes. Two primary forms of melanin exist: eumelanin, which provides black and brown tones, and pheomelanin, which gives a red color. People with darker skin produce more melanin than those with lighter skin. Environmental factors such as sunlight and UV radiation exposure stimulate the production and accumulation of melanin in keratinocytes, causing the skin to darken, which serves to protect against UV damage and folic acid breakdown. However, excessive melanin can impede vitamin D production. Other pigments like carotene, which offers a yellowish tint, and hemoglobin, which provides a pinkish tint, also contribute to skin coloration, particularly in individuals with lower levels of melanin.