Ans. is 'a' i.e., Erythema annuiase cetrifugam o Erythema annulare centrifugum : an asymptomatic or pruritic eruption of variable duration. The eruption may be associated with an underlying disease (eg, infection, malignancy, sarcoidosis, other systemic illness)o The eruption begins as erythematous papules that spread peripherally while clearing centrally. These lesions enlarge at a rate of approximately 2-5 mm/d to produce annular, arcuate, figurate, circinate, or polycyclic plaqueso Lesions demonstrate a predilection for the thighs and the legs, but they may occur on the upper extremities, the trunk, or the face. The palms and the soles are spared.o Erythema migrans: These lesions are typically less numerous, less circinate in configuration, and often accompanied by a history# of a tick bite.o Erythema gyratum repens: EAC can be distinguished from this condition by its slower rate of spread and by its less bizarre configuration. Also, erythema gyratum repens is almost always associated with an underlying malignancy.o Erythema marginatum rheumaticum: This is a nonscaling gymate erythema that by definition is found in association with rheumatic fever (10-18% of patients with rheumatic fever).