(I'LL GIVE BRAINLIEST AND EXTRA POINTS TO WHO EVER HELPS ME!! :D) How did Paul Revere prepare this document?

A) Interviewed witnesses of the Boston Massacre
B) Participated in the Boston Massacre
C) Read excerpts about the Boston Massacre in the newspaper
D) Witnessed the Boston Massacre

(Here is the image) :

Using mr smith and his id, identify two potential internal validity threats that might affect the a—b design. tell me how that threat might impact conclusions in the a—b design. note #1: you cannot use maturation (since i already did that one for note #2: there are some mr smith id threats that won’t have much impact in a single case design.