A．who it was thatB．who was it that

C．it was whoD．who was it

【答案】A

【解析】

选A，主要考查你对 宾语从句，强调句 等考点的理解。find out后的宾语从句是强调句型，此时的语序是，引导词+it is that ,故选A，一定要用陈述语序。