Correct Answer: loss of melanin in epidermal cells

Solution : The correct option is the loss of melanin in epidermal cells.

Grey hair is produced by a reduction in melanin synthesis inside hair follicles. Melanin is the pigment that gives our hair, skin, and eyes their colour. As we age, the melanocyte cells within our hair follicles generate less melanin, resulting in a decrease in pigment. This loss of pigment causes hair strands to lose their colour, and appear grey or white.