单选题 Although there are weeks of negotiations ahead, and perhaps setbacks and new surprises, leaders of both parties are ______ that their differences can be resolved.

A、 optimistic
B、 perplexed
C、 incredulous
D、 uncertain

【正确答案】 A

【答案解析】(optimistic乐观的)。句意为：尽管离谈判还有几个星期，也许会出现挫折和新的意外，但是双方领导人都很乐观，认为他们的分歧是可以消除的。B．perplexed感到困惑的；C．incredulous不轻信的；D．uncertain不确知的。