What can excessive secretion of sebum lead to on the skin?

Excessive secretion of sebum can lead to oily skin, as sebum is the natural oil produced by sebaceous glands to lubricate and protect the skin. When the production of sebum is increased, it can result in an overabundance of oil on the skin's surface, leading to a shiny appearance. This condition can also contribute to other skin issues, such as acne, as the excess oil can trap dirt and bacteria, clogging pores and leading to breakouts.

While dandruff is associated with the scalp and often results from a different type of skin condition, aging is related to reduced sebum production and skin dryness, not excess. Dry skin occurs when there is insufficient sebum to maintain moisture levels. Thus, the correct answer directly addresses the consequence of high sebum levels, which is oily skin.