What did an abundant supply of slaves and the wealth from tribute, plunder, and trade allow egyptian pharaohs and other rulers to do? create large armies to defend the borders of their empires conquer new territory in regions far from their empires build huge monuments and temples and develop infrastructure develop new types of art and architecture

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.