It's hard to imagine him ____ Without it.

A- Existing
B- Exists
C- To exist
D- Does not exist

I am in a jam , because we have rules for "imagine" , the rules are as the following: 1-it is hard to believe/imagine/see/know etc
2-it is difficult/easy/possible/impossible etc to imagine sth
3- imagine sb in/with/without sth
4- imagine sb doing sth.
What I notice here , the
sentence(question) isn't similar to the rules , there is a difference between them.

I think the answer is "doesn't exist(NOTE HERE THE ANSWER WILL BE NULL(EMPTY SET) " because we can't gather(collect) "without and imagine sb doing sth" , for(because) we have "it" after "without" which refers to"exist, meaning his photo or body...etc". We can also say: it's hard to imagine him existing(without it), They are the same thing(meaning) If you want another answer , the new answer must be "existing" but I don't prefer it.
If you have the correct answer, tell me , okay!