Skin is the largest organ of the body and it has several glands at various locations of the body.
Sebaceous glands (A) secrete oily or waxy substance for rendering the skin relatively “waterproof”. They are exocrine glands.
Apocrine glands (B) are modified glands that develop in areas abundant with hair follicles and are present in certain parts of the body like those in breasts produce milk fat, ears produce wax, etc. Apocrine glands secrete their products into the hair follicle.
Endocrine glands (D) produce hormones and secrete them directly into the blood. They don’t have ducts for secretion.
Therefore, options A, B and D are incorrect.
Eccrine glands (B) are the major sweat glands and distributed throughout the body. They are present particularly at high concentrations in the palm and are responsible for producing watery “sweat”. Eccrine glands discharge their secretion directly to the skin surface, via a duct.
Therefore, option (B) is correct.