<span>The correct answer is the plow. Before plows, there was no way to use the land to its full extent. Shovels couldn't dig far deep in and it was kind of pointless, while plows were pulled by bulls and horses way before the tractor was invented. The sickle was just a long knife useful for cutting crops but other things could be used too.</span>
Its C (inform) because the author is trying to inform the people about the lessons about human behavior.
I hope this was helpful.
1. charging an official with a misdeed (a crime): impeachment
2. chosen; appointed (suggest someone for an election, job): nominated
3. to improve; to change: to make into a better quality: amended
4. reverse; change to the opposite position: overturn
5. whether the law or act is constitutional: constitutionality
6. court determination of constitutionality of laws passed: judicial review
