(C) For the longest time Europeans and other outsiders could not travel into central Africa due to the various disease they were not immune or accustomed to, as it meant almost certain death for anyone not native to the area.
The idea of equality was radical in the 1700s was because they felt like equality really needed to be found and used. Some people liked and disliked equality and everyone felt different about it.
A secondary source could be someone that maybe discovered the body or is doing evaluations to see why or how he died, like a doctor for instance it would be a secondary source because............the doctor was not there and he did not watch so....and if he wrote about it then that would be a secondary source! :) <3 hope this helps!