getIdOfSelectedChoice.js

Qualtrics.SurveyEngine.addOnload(function () {
    this.questionclick = function(event,element) {
        if (element.type == 'radio') {
        	var el = document.getElementById(element.id);
			var parent = el.parentElement;
			var img = parent.querySelector('span img');
			Qualtrics.SurveyEngine.setEmbeddedData('Winner', img.id);
        }
    }
});