What a different man he is ___he was fours ago. Afrom what Bto whom Cwith whom Dby whom

选A。

空格前的句子“What a different man he is”可以看做是“He is a different man”的感叹句。be different from --- 和--- 不相同。 整句话的意思是：他和四年前是多么的不同啊！