Respuesta :
"build huge monuments and temples and develop infrastructure" would be the best option, since this labor and financial supply allowed them to take time on massive projects.
I believe the answer is: build huge monuments and temples and develop infrastructure
At that that time, the slaves owned by the Egyptian government was forced to work in building infrastructures such as pyramids, altars, ceremonial buildings, temples, and several mechanisms that are necessary to sustain the Agricultural process in egypt.
On top of this, some of them often traded or given as some sort of presents to other empire to build bilateral relationship with Egypt.