What does historiography suggest about history?

Which is the best example of a primary source ducument useful in the study of history ?

Anthony johnson, an african who arrived in virginia in 1621, a. learned the powhatan language and became a translator for governor thomas dale. b. owned slaves. c. translated the king james version of the holy bible into indian and african dialects. d. was the first slave who purchased his freedom with earnings from growing tobacco.

Why do you think jefferson thought lewis was qualified to explore the louisiana purchase? ?