What accounts for the devolopment of manorialism in western europe after the fall of the roman empire?

I’m annoyed but glad that my history teacher left and quit her job as a teacher to become a flight attendant

Following archduke franz ferdinand's assassination, austro-hungarian leaders: a. aided the ottoman empire in its campaign to keep serbia under its control. b. executed nearly all prominent serbs living in austria-hungary c. threatened to invade serbia if serb leaders did not agree to a set of strict demands. d.. formed an alliance with great britain to protect austria-hungary from future attacks.

Then write 1-2 paragraphs describing one individual you believe has made a significant contribution to florida and united states history. in your response, explain why this individual's contribution was significant.