I have two exercises which I don't exactly understand. I've already known that どちら is more polite form from どこ. This two could ask about place and "what/which one" ."nan" asks about "kind of company", isn't it? I've checked the answers and it looks like that:
A: おくには なん／どこ ですか。
Correct answer here is "doko" and I suppose it's because of the meaning "what country". Could it be wrong with "nan"?
A: かいしゃは なん／どこ ですか。
Correct answer is "nan" and I don't understand it! Why it couldn't be "doko"? Please explain me that.