One of the three answering group circuits

There are many types of quiz circuits, including relay type, electronic type, thyristor type, integrated circuit type, single board computer
type, etc.
    Here are some of the simplest answering circuits. Circuit requirements: When the button of any answering group is pressed first, the indicator light
of this group will light up and the bell will ring. Before releasing this button, pressing other buttons will have no effect ( the indicator light will not light up). Release the button and the circuit is restored. As shown in the circuit diagram , it requires three relays.