Final answer:
The proper response is 'melanocytes' since everyone has roughly the same number of melanocytes, which produce melanin, determining hair and skin color.
Step-by-step explanation:
The correct answer to the question is c) Melanocytes. All people have about the same number of melanocytes, regardless of skin color. What varies from person to person is how active these cells are in producing melanin. Melanin is the pigment that determines the color of our hair and skin. The differences in skin color among individuals arise from the varying levels of melanin production, which is influenced by genetic factors and environmental cues such as exposure to UV light.