Answer: A The Mongols struggled to govern such an enormous empire.
I believe the answer is: D. They lost control of territory in the Middle East, but preserved Turkey's political independence.
When Turkey decided to enter the world war I, they are forced to retract the military power that they posted on middle Eastern to aid Germany in the war. This make their influence in middle east become significantly weaker and causing them to lost many territories in middle East.
Maybe
Westward Expansion-African American’s
Or
The African American’s during Westward Expansion
I hope this helps!