Which of the following factors led the roman empire to split around the fourth century ce?
a. foreign religions became more popular in the western parts of the empire.
b. roman citizens established a new republic in the eastern parts of the empire.
c. foreign invaders destroyed the empire and divided it into many kingdoms.
d. roman leaders were unable to control areas far from the roman capital.

2686-2181 bce-- "egyptian civilization developed along the nile river in large part because the river’s annual flooding ensured reliable, rich soil for growing crops."

1069-664 bce-- "ancient egyptians developed wide-reaching trade networks along the nile, in the red sea, and in the near east."

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain