The correct answer is D.
Mamluk is an Arabic designation for a slave.
The Mamluks were slave soldiers who rebelled against their rulers to establish their own state in Egypt.
They were purchased as property but their status was above ordinary slaves, they were considered warriors and 'enslaved mercenaries'.
Due to their relentless pursuits of warfare and zealous ambition, they overthrew their masters, defeated the Mongols and established a dynasty that lasted 300 years.
At their height, the Mamluks controlled Egypt, northern India, parts of Syria, Jerusalem and Iraq.