The correct answer C. Papuloerythroderma of Ofuji.
The description of sparing of the abdominal creases in a patient with generalized erythroderma is consistent with Papuloerythroderma of Ofuji. This sign is called the deck-chair sign.
Drug reaction with eosinophils and systemic symptoms (DRESS) syndrome, mastocytosis, pityriasis rubra pilaris, and secondary syphilis are other causes of erythroderma but are less likely in this patient with the deck-chair sign.
Desai K, Miteva M, Romanelli P. Papuloerythroderma of Ofuji. Clin Dermatol. 2021;39(2):248-255. doi:10.1016/j.clindermatol.2020.10.017