Back button function on android

I made a game with menu option at start which has several option like start, help, controls etc.
when a player click them they are on a new screen and there is a back button on them if they press it they will sent back to home screen.
I want to know how to do like if a player clicks the back button of their android device it do the same thing as the back button on that page do
the button i m talking about is the back button of their android device, which if the player press it closes the game
Is it possible?