1. The police haven't confirmed if the man has _______ to do with the murder.
2. She lost herself in doing homework so that she didn't hear ____ knocking at the door at all.
B. anybody [. . .]
What is my question?
Whatever the answer is, what would “some-” mean behind in both 1 & 2?
You're right that the default, "unmarked" choices for each question are "anything" and "anybody," respectively. However, "something" and "somebody" are also possible, given the right context. Those choices are not ungrammatical.
"Something" would work in (1), for example, if there were an assertion in the context that the man had something to do with the murder. The police, the sentence is saying, haven't confirmed if that is the case.
"Somebody" would work in (2), similarly, if it were established in the context that somebody was knocking at the door while she was lost in doing her homework. The sentence is saying she did not hear that that was taking place at the time.