I agree most with A & C. All you experience when landing is not enough lift to maintain height. The wing probably isn't at or past critical alpha. In my limited experience the stall warner may be sounding on some a/c in the flare, but the stall had yet to take place.
If the question is interpolated to heavies, then my personal interpretation of the theory is that the wing certainly isn't stalled on touch down!
I do disagree with n5296s a little. My understanding is that a stall is an absolute thing and is related only to the AoA, is measurable and has a defined constant start point for a set configuration; the critical AoA.
If the wing were near the stall with a wing down landing, would there not be a severe risk of a sudden wing drop on the up wing as the down aileron would effectively increase the AoA on that tip.