Student or Learner
Can one say:
a. He is a man that is a crime not to like.
b. He is a man that it is a crime not to like.
c. He is a man who is a crime not to like.
d. He is a man whom it is a crime not to like.
I had asked a similar question to this. That was about objects and this is about humans.
The point under discussion in the other thread is not affected by whether objects or humans are involved in the '(it) is a crime (not) to' sentence. I suggest you wait until the question is settled in that other thread.
A fresh discussion here might lead to more confusion.