after selecting any one option, the others become unselectable(disable)

How to do this, after selecting any one option, the others become unselectable(disable) . Please hint according to the given code snippet.
$(".mcq").on("click","li", function(){
$(this).addClass("select");
where
.mcq li.select {
background:#68c9c6;
color:#fff;
animation:zoomOut 300ms ease;
}