Why does your skin remain red after a bad sunburn? a) Blisters form, lifting the epidermal layer. b) Inflammation causes increased blood flow. c) Loss of sweat glands in the dermal layer d) Damaged epidermis cells are sloughed off.'

Skin remains red after a bad sun burn because:

inflammation causes increased blood flow.

Explanation:

When our skin is exposed to sun rays , the epidermal layer starts getting damaged. The damage to the cell caused by  sun rays triggers the  melanin secretion. Increased secretion of melanin results in darkening of the exposed region .

However, the damage and inflammation to the skin increases blood flow to the skin, this causes reddening of the skin.