The passage suggests which of the following about most existing maps of Native American la

A．They do not record the migrations of Native American tribes.

B．They have been preserved primarily because of their connection with treaties involving land transfers.

C．They tend to reflect archaeological evidence that has become outdated.

D．They tend to be less accurate when they are based on oral reports than when they are based on written documents.

E．They are not based primarily on the mapmakers’ firsthand oberservations of Native American lands.