What events caused the decline of the Abbasid dynasty?
A. The Abbasids willingly gave up their lands to the Seljuk Turks and the Mongols.
B. The Abbasid empire fragmented, and other peoples gained control.
The invaders from Spain created small kingdoms throughout the former empire.
D. The Umayyads and the Abbasids waged a civil war that destroyed the empire.