Answer: Layer
Explanation:
Most likely, in this case, the word ''stratum'' means layer.
The stratum corneum - epidermis, has the meaning of the outer layer of the skin.
The stratum lucidum - has the meaning of a thin and clear layer of dead skin cells that are found in The stratum corneum(epidermis).
The stratum basale is considering the deepest layer of The stratum corneum(epidermis).
