I'm using the jQuery plugin template from CSS-Tricks, but I'm having a problem with the default options.

(function ($) {
  $.lilRWDMenu = function (el, options) {
      var base = this;
      base.$el = $(el);
      base.el = el;
      base.$el.data("lilRWDMenu", base);
      $.lilRWDMenu.defaultOptions = {
          mainMenuClass: 'main-menu',
          rwdMenuClass: 'rwd-mobile-menu'
      };
      base.init = function () {
          base.options = $.extend({}, $.lilRWDMenu.defaultOptions, options);
      };
      base.init();
  };
  $.fn.lilRWDMenu = function (options) {
      return this.each(function () {

          var mainMenuObj = options.mainMenuClass,
              rwdmenuObj = options.rwdMenuClass;
          console.log(mainMenuObj );
          console.log(rwdmenuObj);
      });
  };
})(jQuery);

For some reason the default options are coming back as 'undefined'.

I can't figure out why it's not working, so if anyone can check my code for me that'll be great.