Final answer:
Dawn is likely dealing with acne vulgaris, a skin condition common among teenagers due to hormonal changes that lead to blocked hair follicles and bacterial infection, causing pimples and potential scarring. The correct option is A.
Step-by-step explanation:
Dawn is likely experiencing acne vulgaris, a common skin disorder characterized by pimples, pustules, whiteheads, blackheads, nodules, and other lesions primarily on the face, upper back, and chest. This condition is particularly prevalent in teenagers due to hormonal changes that cause an overproduction of sebum, which can block hair follicles when it accumulates along with keratin.
The resulting blockage, initially a white plug that turns black when oxidized, may become infected by acne-causing bacteria such as Propionibacterium and Staphylococcus. This can lead to inflammation, redness, and potentially scarring. The dermatologist's prescription of oral tetracycline and retin-A is a standard treatment aimed at reducing the bacterial infection and promoting skin cell turnover to unblock pores.