The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
The stratum basale (also called stratum germinativum) is the deepest epidermal layer consisting of a single row of basal cells, or germinative cells, that are undergoing rapid mitotic divisions. These cells are sometimes called stem cells because their mitotic divisions replace the more superficial keratinocytes that are lost or shed at the surface. The skin is supplied with three types of cutaneous glands, all of which are formed from the epidermis during foetal development.