The ultimate question, would not be multiple choice.
Who said anything about multiple choice? If Q is a deterministic question asked in an exam, and X is an complete answer to it scoring 100% (whether this be a piece of music composition, an answer with full annotated working to a mathematical problem, or a four page dissertation on the religious changes that happened under Henry VIII's rule in England), then all of the children in the class can submit X as their answer and receive full marks.
Hence, if anyone posts "The answer to Q is X" on the Internet, then typing "The answer to Q" into Google yields X - an answer that gives full marks in the exam.
Hence, it becomes possible to receive full marks in the exam by knowing how to Google, regardless on the complexity of the question.