Your answer would be D. hope that you pass!
Answer:
A census; had an accurate account of the number of people that lived in the states.
Explanation:
I don’t know if this is what your book is wanting but this is all I could find.
Hope this helps!
It's B because all the rest of them are required.
The most important purpose of irrigation was to give water to soil and fertilize so that growing conditions were great for growing crops
