Three stand before you. Only one holds the passcode. But none will answer plainly.
Ada always tells the truth.
B25Y tells the truth only when Ada is lying.
Charles answers randomly-truth or lie, you won't know.
You may ask one question to one person only. (The puzzle will automatically reset after 10 seconds, each round will have a new passcode holder.)
What question will you ask to discover who holds the passcode?