Pfizer's（美国辉瑞公司的）patent in China, which is valid until 2014, could bar （）producers from a market worth around 200 billio

Pfizer's（美国辉瑞公司的）patent in China, which is valid until 2014, could bar （）producers from a market worth around 200 billion Yuan.

A.vulnerable

B.domestic

C.diligent

D.pessimistic

正确答案：domestic