Adam is questioned first as the one chiefly responsible for the conduct of both of them. God does not deny that Adam and Eve were naked, but presses upon them the real cause of their shame.
The immediate effect of sin is that human beings cover themselves with a web of deceit. We attempt to hide from the eyes of the Lord, but we also seek relief from our own consciences and so we wish to deceive ourselves as well, and God must strip bear this deception before we are ready to have any honest dealing with him. God draws him to repentance, but he will not repent. God invites him to state his case, and to plead for forgiveness or for mercy, but he will not do it. The man who was a perfect man is now corrupted and tainted.