C .,different jobs for different workers
A country needs rules about citizens cause in reality you cant have random people, bad record or not, coming in your country and just being a citizen instantly without any proof of trust, little do they know they could be a terrorist with the rights of a citizen just cause theirs no way to justify who's one or not.
Answer:
The battle between the Monitor and the Merrimac (This was the ship's name when it was a US Navy ship. The CSA renamed it the Virginia) was the most famous naval encounter of the American Civil War. It is important because it showed that the era of wooden ships was coming to an end.