Question

Please help! What role did the practice of devshirme play in the maintenance of a strong and loyal standing army?

It ensured that the sultan would have a hostage if the people he conquered tried to rebel.
It cost less money to fill the army with slaves than to pay free Muslim fighters, who might leave for bettter wages.
It ensured that the army contained soldiers without loyalty to other Muslim tribes or families.
It prevented Christians from planting spies or resistance fighters in the sultan's army.