A 36-year-old factory worker developed itchy,annular scaly plaques in both groins.Application of a corticosteroid ointment led to temporary relief but the plaques continued to extend at the periphery.The most likely diagnosis is:

• A. Annular lichen planus.
• B. Tinea cruris.
• C. Erythema annulare centrifugum.
• D. Granuloma annulare.