_____ their policy can be changed the future for that country will be indeed bleak. A: Even if B: Unless C:Now that D:As long as

_____ their policy can be changed the future for that country will be indeed bleak.
A: Even if
B: Unless
C:Now that
D:As long as

B.意思是“除非”
句子翻译：除非他们的政策改变,否则国家的前景十分暗淡.