The crusades were considered a turning point in history because the pope urban 2 wanted the christians to fight the muslims so that they could have back the control over the holy lands
I think that the answer is D
Since Robespierre was considered of high morality and virtue, your answer is virtue and goodness.
Hope this helps!
If you are talking about WW1, then the 3 factors are the Zimmerman Telegram, The sinking of the Lusitania, and economic interests