句意：屠呦呦一登上舞台观众即刻响起雷鸣般的掌声。no sooner…than…“一…就”，引导时间状语从句，主句用过去完成时，从句用一般过去时，正常语序是：Tu Youyou had no sooner stepped on the stage than the audience broke into thunderous applause；当no sooner…than…置于句首时，主句要倒装，即把助动词放于主语之前,因此A正确。