Why is "to" being used after "confusing"? Would it change the nuance of the sentence if I omit "to" here?

Rebecca

This is a good question. The speaker is directing the question towads someone else, so “to” is used here. In addition, “is” is used before “confusing,” so “to” is required to make the sentence grammatically sound. If we remove these two words, we can change the sentence without changing its meaning. Ex: What part of “kills humans” confuses you? = What part of “kills humans” is confusing to you?