A3 mm thick laceration of the skin of the anterior forearm would not harm the layer of the epidermis.

The correct answer is - stratum basale.

Explanation:

The stratum basale is the deepest layer of the epidermis which is made up of cuboidal or columnar cells. As it made the basal layer of the epidermis which is the outer layer of the skin of all members of mammals. It is also known as the stratum germinativum.

It is the only layer that will be unaffected if a 3 mm thick laceration will practice on the anterior forearm as it is a deepest layer of the epidermis which is essential as it creates the keratinocytes that later move to upper layers.

Thus, the correct answer is - stratum basale.