题目解析:
mutual: 共同,exclusive想到exclude再想到include,所以是不包含的,排他的,那mutually exclusive的意思就是不相容的,互相矛盾的,所以答案应该是A。对应原文:Speculation on the origin of these Pacific islanders began as soon as outsiders encountered them, in the absence of solid linguistic, archaeological, and biological data, many fanciful and mutually exclusive theories were devised.前文说由于缺乏各方面证据,各种各样的想象的和什么样的理论被设计出来。从语境看,应该是五花八门的理论,各不相同的理论,所以A代入后非常符合这个语境。