_________ impressed the visitors

_________ impressed the visitors deeply was _________ the workers made it with their hands.
A、What, that
B、That, that
C、What, what
D、That, what
【正确答案】：A
【题目解析】：was 后面的表语从句要用that引导；因此可排除选项C和D；主语从句中缺少主语，能在从句中充当主语的只有what，所以选A。