Which of the following is NOT a type of gland in the skin?

The correct answer is based on the classification of glands found in the skin. Sudoriferous glands and sebaceous glands are indeed types of skin glands. Sudoriferous glands are responsible for sweat production, playing an essential role in regulating body temperature and excreting waste products through perspiration. Sebaceous glands, on the other hand, produce sebum, an oily substance that helps to lubricate and protect the skin and hair.

Exocrine glands refer to a broader category of glands that secrete their products through ducts to the surface of an organ. Both sudoriferous and sebaceous glands fall under this classification, as they release their secretions directly onto the skin's surface.

Nephron glands, however, do not exist in the context of skin physiology. Nephrons are the functional units of the kidney involved in filtering blood and producing urine. Therefore, they are not related to the structure or function of skin glands. This makes nephron glands the only option that does not pertain to the types of glands found in the skin.