Which of the following is a valid way to determine whether a Checkbut ton has been selected?

You associate a different IntVar object with each Checkbutton widget. When a Checkbutton widget is selected, its associated IntVar object will hold the value $1.$ When a Checkbutton widget is deselected, its associated IntVar object will hold the value $0.$

You call each Checkbutton widget's is$\_$selected method. If the method returns True, the widget is selected. Otherwise, the widget is not selected.

You check the contents of the checkbutton$\_$selected list, which will hold the names of the currently selected checkbut ton widgets.

You pass each checkbutton widget as an argument to the is$\_$selected method. If the method returns True, the widget is selected. Otherwise, the widget is not selected.