GWD6-Q40:

It 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?

A.It fails to establish whether bacteria actually developed on Mars.

B.It fails to establish how likely it is that Martian bacteria were transported to Earth.

C.It fails to consider whether there were means other than meteorites by which Martian bacteria could have been carried to Earth.

D.It fails to consider whether all bacteria now on Earth could have arisen from transported Martian bacteria.

E.It fails to consider whether there could have been strains of bacteria that originated on Earth and later died out.

老师这个题E为啥不选哪？答案D想想好像是对的，但是E是说来自于地球的细菌，之后就死光啦，是不是错就错在对象问题，如果改成M是不是就对啦？