A、It was very expensive. B、Henry lost it. C、Mary didn’t like it. D、It was very big. A本题要求对词组cost an arm and a leg做出正确的解释，意思是cost

M：Did you see the diamond ring Henry gave to Mary?
W: I sure did．It must have cost him an arm and a leg．
Q: What does the woman imply about the ring?