The outer layer of the skin is called the epidermis. This layer is formed by epithelial cells. The dead layer of cells is called the stratum corneum.
She is a medicinal chemist, hence one of her main assignments would be to produce drugs for certain diseases. This could involve several subtasks like identifying chemical substances, analyze which substances can dissolve another and finding catalysts or enzymes for certain reactions and also simpler procedures like annihilating a base with an acid.
Kingdom since it’s the largest from all the choices there