Most skin problems are caused by:

The correct answer is that most skin problems are caused by sebaceous glands. These glands are responsible for producing sebum, an oil that helps to lubricate and protect the skin. When sebaceous glands become overactive, they can lead to excessive oil production, resulting in conditions like acne, which is one of the most common skin issues.

Additionally, if sebaceous glands block hair follicles with excess oil and dead skin cells, this can create an environment conducive to bacterial growth, further exacerbating skin problems. Maintaining a balance of sebum is crucial for healthy skin, and dysfunction in these glands plays a significant role in various dermatological disorders.

Fibroblasts, keratinocytes, and melanocytes each have their own important functions in skin health and integrity, but they are not typically the primary cause of common skin problems like acne and oiliness. Fibroblasts are important for collagen production and wound healing; keratinocytes are vital in forming the skin barrier and producing keratin; and melanocytes are responsible for pigment production in the skin, affecting skin color and providing some protection from UV radiation. However, these functions do not directly link as frequently to skin problems as the activity of sebaceous glands.