Help the CSS WG!

What syntax makes most sense to you for drawing two solid borders around a box, a 1px white on the inside and a 1px black on the outside?
Pic for reference in next tweet.

A) border: 1px solid white, 1px solid black;

B) border: 2px solid stripes(white, black);

C)
border-width: 2px;
border-style: solid;
border-color: white, black; /* or black, white */

(we’re trying to decide syntax, not order, so try to ignore the order if black first makes more sense to you)