A nurse is caring for a client who has widespread psoriasis. The nurse should prepare the client for which of the following treatments?

A. Administration of isotretinoin: Isotretinoin is primarily used to treat severe acne vulgaris by reducing sebaceous gland activity and keratinization. It is not indicated for psoriasis, as it does not target the immune-mediated hyperproliferation of keratinocytes that characterizes psoriatic lesions. Using isotretinoin would not effectively manage widespread psoriatic plaques. B. Exposure to photochemotherapy: Photochemotherapy, or PUVA therapy (psoralen plus ultraviolet A light), is a common treatment for widespread psoriasis. Psoralen sensitizes the skin to UVA light, which slows the rapid proliferation of skin cells and reduces inflammation. This therapy is effective for extensive plaques that are not manageable with topical treatments alone. C. Radiation therapy: Radiation is not used to treat psoriasis due to the high risk of long-term skin damage, carcinogenesis, and systemic effects. While UV light is beneficial in controlled phototherapy for psoriasis, ionizing radiation is not appropriate and is not part of standard dermatologic care. D. Topical application of antibiotic ointment: Antibiotics are used to treat or prevent bacterial infections but do not address the underlying immune-mediated hyperproliferation in psoriasis. While secondary infection of psoriatic lesions may occur, routine antibiotic ointment is not a primary treatment modality for widespread psoriasis.