[逻辑小分队] 求解各位大神一道GWD逻辑题目！！

t is theoretically possible that bacteria developed on Mars early in its history and that some were carried to Earth by a meteorite. However, strains of bacteria from different planets would probably have substantial differences in protein structure that would persist over time, and no two bacterial strains on Earth are different enough to have arisen on different planets. So, even if bacteria did arrive on Earth from Mars, they must have died out.

The argument is most vulnerable to which of the following criticisms?

• AIt fails to establish whether bacteria actually developed on Mars.  分析A选项
• BIt fails to establish how likely it is that Martian bacteria were transported to Earth.  分析B选项
• CIt fails to consider whether there were means other than meteorites by which Martian bacteria could have been carried to Earth.  分析C选项
• DIt fails to consider whether all bacteria now on Earth could have arisen from transported Martian bacteria.  分析D选项
• EIt fails to consider whether there could have been strains of bacteria that originated on Earth and later died out.  分析E选项
  
  请问，D和E的甄选。我觉得E也是可以weaken题目中的conclusion的啊？？？E，如果地球上的细菌在以前死光了，那么目前地球细菌不就是只剩下火星的细菌了吗？如果没有死光，不就是weaken结论了吗？实在不明白E错在哪里？