If A + B means A is the brother of B, A - B means A is the sister of B, and A × B means A is the father of B, what is the relationship of C if A + C - B means A is the brother of C and C is the sister of B?
Answer: A. C is A's sister
According to the codes, if A is the brother of C and C is the sister of B, then C must be A's sister.