Final answer:
A follicular cast is a dermatological condition and would be classified as a secondary lesion, representing a response or change from an original primary skin condition.
Step-by-step explanation:
The term "follicular cast" refers to a dermatological condition, not an ovarian follicle or an immunological response. However, when we consider skin lesions in dermatological terms, primary lesions are directly associated with the disease process, while secondary lesions are those that evolve from primary lesions or are manipulated lesions (e.g., a scratch or an infection superimposed on the primary lesion). Since follicular casts can be considered a change that occurs in response to a primary skin condition (like a result of inflammation or an underlying skin disease), they are most accurately described as a secondary lesion (B).