Question

exposure to ultraviolet light darkens skin by stimulating synthesis of multiple choice melatonin. carotene. hemoglobin. cyanin. melanin.

Explanation:

Melanin is a pigment that gives skin its color. Ultraviolet light stimulates skin cells to produce more melanin, leading to skin darkening. Melatonin is a hormone related to sleep - wake cycles. Carotene is a pigment found in plants and can affect skin color to some extent but not in response to UV light in the same way as melanin. Hemoglobin is in red - blood cells and related to oxygen transport. Cyanin is a plant pigment.

Answer:

E. melanin