The healing of a shallow cut in the skin results from an increase rate in mitosis in cells of the skin layer called

Epidermis

Explanation:

The epidermis is the most external layer of skin. This layer has the cells that will make mitosis and heal the cut, as well as give the pigmentation to the skin.

The second layer is called dermis. This layer contains blood and lymph vessels, nerves, hair follicles and sweat glands. It will give protection and nutrients to the epidermis.

The last layer is called hypodermis. This layer has bigger blood vessels and nerves that will go to the dermis. Another function is to attach the skin to the muscles.

"a.) well–developed vascular system."