The correct options are
A Aurangzeb spent too much money on wars.
B Efficiency of Mughal administration decreased.
C Mughal emperors did not keep the powerful mansabdars in check.
Mughal empire declined due to many reasons. Aurangzeb's long war in the Deccan strained the military and the financial resources of the empire. Also, the efficiency of the Mughal administration decreased. The later Mughal emperors could not control their powerful mansabdars.