困扰我许久了的问题,介词结构

24.   Just as plant species native to regions with browsing mammals evolved many natural anti-browser defenses (such as sharp spines and toxic chemicals), so humans in malarial regions have evolved dozens of chemical defenses against malaria.

(A) so humans in malarial regions have evolved dozens of chemical defenses against malaria

(B) humans in malarial regions have been evolving dozens of chemical defenses against malaria

(C) there has been, in malarial regions, an evolution of dozens of human chemical defenses against malaria

(D) dozens of chemical defenses against malaria have been evolved by humans in malarial regions（A）

(E) similarly, in malarial regions, humans have evolved dozens of chemical defenses against malaria

答案A,我想知道E为什么不对，我们撇开just as.. so.. 的句型不谈，我看解释是说in malarial regions修饰模糊，可是我怎么觉得和A一样的？A是在疟疾之地的人们，E为在疟疾之地，人们

介词短语困扰我许久了，好多选项都是因为他而迷惑，请大家帮我好好解答下介词到底应该怎么修饰？