Radio Button Component Label Width in AS3

var answerX:int = -220;
var answerY:int = -85;
var spacing:int = 25;
var theUserAnswer:int;
 
var answerChoices:Array = new Array("This is text for option a","This is text for option b","This is text for option c","This is text for option d");
 
 
 
 
 
var myGroup:RadioButtonGroup = new RadioButtonGroup("group1");
myGroup.addEventListener(Event.CHANGE, changeHandler);
	for(var i:int = 0; i < 4 ; i++) {
		var rb:RadioButton = new RadioButton();
		rb.textField.autoSize = TextFieldAutoSize.LEFT;
 
		rb.setSize(550,150); // This does not work
 
		rb.useHandCursor = true;
		rb.label = answerChoices[i];
		rb.group = myGroup;
		rb.value = i + 1;
		rb.x = answerX;
		rb.y = answerY + (i * spacing);
		rb.textField.wordWrap = true;
		addChild(rb);
	}