What does a historian require in order to make a valid historical interpretation about an event?
A. A well-defined thesis related to the event
B. An inference about what caused the event to occur
C. Primary or secondary sources related to the event
D. Several possible claims to make about the event

Which of these would be most useful in studying the effect of germs exchanged between the new and old worlds? a. a graph showing the number of europeans between 1492 and 1600. b. a graph showing the number of native americans between 1492 and 1600. c. a primary source description of the symptoms of an unknown disease affecting native americans in 1492. o d. a primary source description of the symptoms of an unknown disease affecting europeans in 1492.