According to the answer sheet, B is the answer. Does that make A incorrect? What difference do these 2 make in the meaning? Plus, is B more polite? It seems kind of frustrated to me.
1 Answer
Well, either is grammatically correct, but they have different meanings.
So, "Carry the luggage for me, won't you?" implies the opposite: you should carry the luggage. It is therefore a polite offer. "Carry the luggage for me, will you?" implies the opposite: you shouldn't carry the luggage.
"will you" could be used when the speaker is frustrated that somebody hasn't done something already. It would usually have the word "just" at the beginning:
Just carry the luggage for me, will you?
I guess the answer sheet said B was correct, as "will you" is a bit "aggressive" and may not be the best answer for practice.
More information on will you vs won't you here