What is an example a secondary source a historian might use in a study of the negative effects of the Mongolian Empire on Europe?(1 point)
Responses
a. the 1353 painting The Battle of Leignitz by an unknown artist
b. a letter written by English philosopher Roger Bacon
c. an excerpt from The Travels of Marco Polo , written by Marco Polo in 1300 CE
d. the eyewitness account of the destruction of Kiev by Giovanni da Pian del Carpine in 1246