B. Deer skins.
Why? Probably because back in the days Indians used to be extremely talented when it came to hunting for food, water, and even warmth. I doubt they'd have tools to spare besides bows and most likely rock knives they've hand made to cut down the bone and other stuff to make seasonings with. Building styles? No. Why would the Europeans ask Indians to trade building techniques? I doubt it. B is definitely the answer.