A European living in a country conquered by the Mongols would most likely have a negative perspective on the Mongol Empire due to the violence and destruction associated with their conquests. Therefore, the most fitting description of this perspective would be:
B. The Mongols were responsible for the murder of millions of people in their conquest of European countries.
This perspective reflects the fear and devastation experienced during the Mongol invasions, which were characterized by brutality and significant loss of life.