Final answer:
The subcutaneous layer, or hypodermis, is the part of the skin that provides a protective cushion and stores energy as fat, playing a significant role in insulation and protection of underlying tissues.
Step-by-step explanation:
The part of the skin that provides a protective cushion and energy storage for the body is the subcutaneous layer, also known as the hypodermis. This layer is made up of connective tissue and fat, serving as insulation and a protective padding. The hypodermis holds about 50 percent of the body's fat and plays a crucial role in attaching the dermis to the underlying bone and muscle. It also supplies nerves and blood vessels to the dermis.
It is important to note that the epidermis, which is the outermost layer of the skin, is responsible for protection from environmental damage but does not provide cushioning or store energy. The dermis, located below the epidermis, contains blood vessels and sweat glands but also does not serve the purpose of energy storage. Lastly, the option 'barrier function' refers to the overall role of the skin in protecting the body but is not a specific layer. Thus, the correct answer to the question of which part of the skin provides a protective cushion and energy storage is option b, the subcutaneous layer.