According to Osho, whether A or B is your biological father is irrelevant; you are simply you. Obsessing over paternity only breeds more doubt, because even 'father' may not know—only the mother might. Instead of seeking IBM-like certainty, drop the question and live authentically. Shift attention from origins to awareness, from genealogy to growth; your real parentage is your consciousness, here and now.
Stop worrying about who your dad is; be yourself now, and if it truly matters, only your mom might know.