Which glands produce oil that is connected to hair follicles?

Sebaceous glands are responsible for producing oil, specifically sebum, which is associated with hair follicles. These glands are located in the dermis layer of the skin and are found throughout most of the body, particularly on the scalp and face. The oil produced by sebaceous glands serves several important functions, including moisturizing the hair and skin and providing a barrier to protect against external elements.

The other types of glands listed function differently. Sweat glands, which include eccrine and apocrine glands, primarily produce sweat for thermoregulation and are not connected to hair follicles in the same way that sebaceous glands are. Eccrine glands are involved in regulating body temperature through perspiration, while apocrine glands are associated with scent and become active during puberty. Thus, the nature of the sebaceous glands clearly aligns with the question regarding the production of oil connected to hair follicles, making them the correct answer.