Which of the following is a common feature of solar cheilitis?

Dry lips is recognized as a common feature of solar cheilitis, a condition often caused by prolonged sun exposure leading to damage of the lip tissue. This condition presents itself with various symptoms, but the dryness of the lips is a prominent characteristic. The environmental damage inflicted by ultraviolet (UV) light results in a loss of moisture and hydration within the lip area, causing them to become cracked and dry.

The other choices, while potentially related to skin conditions or changes from sun exposure, do not capture the central characteristic of solar cheilitis as accurately. Swelling of the lips may occur in different conditions but isn't specifically tied to solar cheilitis. Chapping of the cheeks is not a typical symptom associated with this condition, and increased pigmentation does occur in some cases but primarily refers to the hyperpigmentation of the skin rather than the specific symptomatology of dry lips. Thus, dry lips stand out as a definitive and common feature of solar cheilitis.