Question

Didn't you see the man ()? A.I nodded just now B.whom Inodded just now C.I nodded to him just no

Didn't you see the man ()?
A.I nodded just now B.whom Inodded just now C.I nodded to him just now D.I nodded to just now答案是D
但我看到百度说省略了关系词that，也有说省略who,whom的，我觉得应该是that,请帮我解答一下，谢谢

Answer 1

D 定语从句
对谁点头 nod to..所以to 不能省.A和B不对.
完整的句子是Didn't you see the man （that） I nodded to just now
that 省略了.

Answer 2

that既可以指人也可以指物，并且省略的那个在从句中作宾语。所以：
that,who,whom用于该句都正确。
nod是不及物动词，朝某人点头加介词to.