Donald Trump was at a campaign rally when a little girl told him she had a riddle for him... Trump agreed to hear the riddle and the girl said, ""You are your mother's son who is not your brother, Who are you?"" Trump answered, ""I'll figure that out and tell you the next time we see you"" Later, Trump still couldn't figure it out, so he called Bill O'Reilly and asked, ""Bill, here is a riddle. You are your mother's son who is not your brother, who are you"" Bill replied, ""That's easy, it's me"…