The correct answer is C. Subcutaneous fat layer.
The subcutaneous fat layer is the layer of fat that lies beneath the dermis, the layer of skin below the epidermis. It is made up of adipose tissue, which is a type of connective tissue that stores fat. The subcutaneous fat layer acts as an insulator against heat and cold, and it also helps to cushion the body against shocks.
The dermis is the layer of skin that lies beneath the epidermis. It is made up of connective tissue, blood vessels, nerves, and sweat glands. The dermis does not act as an insulator against heat or cold, and it does not help to cushion the body against shocks.
The epidermis is the outermost layer of skin. It is made up of epithelial tissue, which is a type of tissue that lines the surfaces of the body. The epidermis does not act as an insulator against heat or cold, and it does not help to cushion the body against shocks.
Therefore, the subcutaneous fat layer is the correct answer to the question.