Endocrine glands are those that release regulatory chemicals inside the body. Choices A, B, and D are examples of endocrine glands. C mentions sebaceous glands, which are found in the epidermis of the skin and secrete sebum (skin oils) onto the surface of the skin. They have no regulatory function, other than to lubricate and protect the skin. Sebaceous glands are exocrine glands, and are not part of the endocrine system.
