Which caused the decline of ancient egypt’s old kingdom?

a.)conquering invaders
b.)pharaohs losing power
c.)widespread drought
d.)economic hardship

The Old Kingdom is a name given to the period in Ancient Egypt, from 2575 to around 2150 BC. At the end of the Old Kingdom Egypt was experiencing many low Nile floods. Drought conditions caused the collapse of many ancient civilizations around 2200 BC. There is no historical evidence that other tribes invaded Egypt at the end of the Old Kingdom. C ) widespread drought.