When you create a menu option for the Select display type(http://prntscr.com/lcgxju) and turn on "Option Required" in Kitchen->Menus->Menuitem->Menu Options, it doesn't make it required when you add it to cart.
The default option when adding a menu item to my cart would be the option name, in my case, "Size," and if I add it with the option Size selected, it will still work even though I have other options...
http://prntscr.com/lcgyf2 - My cart has 2 items, one without the option and one with an option selected.
http://prntscr.com/lcgww4