@kaia C or D. Ideally just a splash of cream, barely enough to cover the bottom of a mug.
In Candinavia when you ask for a coffee at Tim Horton's, unless you specify black, they assume you want a "double double" (2 cream 2 sugar), but that ends up looking like B and tasting like a coffee donut.
Always found it weird that an order for "coffee" means you're gonna get more than just coffee.
I have heard stories (always second hand) about people whose usual order was "7-11" (7 cream 11 sugar)...