I've been meaning to recap the last SimpleQuiz question for awhile now. You know, the Holidays...
Looking back on multi-paragraph list items, it appears that (to me) option C might be the way to go -- using CSS to modify any default top paragraph padding (as Mark Newhouse suggested using a descendant selector). Using the :first-child pseudo-class would also work, but with mixed support.
But aside from the styling, the real debate could be, if you were to use C -- would you wrap single paragraph list items in paragraphs as well? Seems like overkill, yet strange to have only mult-paragraph items use paragraph tags and the rest just live in <li>s.
I'm not intending to restart the debate -- just some holiday fruitcake for thought.
To me, a list item is just that -- a list item. Not necessarily a paragraph of text. It would seem extraneous to add paragraph tags to all short items for the purpose of making the multi-paragraph items feel more at home. Is there anything wrong with having paragraph tags only on multi-paragraph list items and not single items? I don't think so, but when I re-read the question, it sort of strikes me as unecessary to ask.
Yet, it could also be the time of year. The time where it's hard to get your mind back in the swing of things. When I all I really want to do is watch bad movies while making the best selection I can from an assortment of Russell Stover chocolates.