The famous greek historian, herodotus, once wrote that “ is, so to speak, the gift of the nile.” what did he mean and was he right?

I think he meant that the existence of Egypt was only possible because of the river Nile.

Egypt is a very hostile place to live: it's mostly a very dry desert, where nothing would grow: only because of the water that Nile brings is agriculture and food production possible in Egypt.

In that sense I agree that life in Egypt is the gift of the Nile.

(d) it was complex and capable of highly organized efforts.