What gland is responsible for the overproduction causing oily skin?

The sebaceous gland plays a critical role in skin health by producing an oily substance known as sebum. When these glands become overactive, they can produce excess sebum, leading to oily skin. This condition often manifests as a shiny appearance, enlarged pores, and can contribute to acne development due to the excess oil clogging hair follicles.

The other glands listed, such as the sudoriferous gland, primarily produce sweat, which helps regulate body temperature and does not directly contribute to skin oiliness. The pineal gland is involved in regulating circadian rhythms and does not produce substances that affect skin oiliness. The thyroid gland is responsible for controlling metabolism through hormone production and does not have a direct role in sebum production. Thus, the sebaceous gland is the correct choice when identifying the gland responsible for causing oily skin due to overproduction.