Answer: I would say option 2. Sharp teeth
Explanation:
Due to carnivores eating primarily meat, their teeth need to be sharp to cut, tear, and rip the skin/meat on their prey. (Hope this helped :D )
They didn't really give them a section they were just the lower of the five levels
Answer:
Immigrants to work in steel mills
Explanation:
I don't know if I'm right, but it sounds like it. There was more immigration from Europe, so they must need those immigrants to take jobs at steel mills, to produce munition plants, and to work at stockyards. This is just my best guess.