Rethorical devices are all those which helps an individual to argue successfully, defending his point of view but also convincing people to agree with his saying. That is why rethorical devices can help a student: he can explain himself better, defend his ideas and even convince others to do what he believes to be the best.
I believe its both but if I had to choose one I'd say
you should not chew gum in class because it's rude
Why:
It makes it look like your uninterested and not listening
If you have a cell phone yes, most students would use it for social media but it may also be used for school related topics.
Answer:
B. It suggests that Crusoe has to justify his reluctance to sell a boy into slavery.
Explanation:
Though a bit reluctant to sell a boy into slavery, Robinson Crusoe had no other option than to sell Xury to the Portuguese sailor as he needed money. Also that he himself is not capable of taking care of anyone as he is also just a young man. And it should also be noted that it was this same Portuguese sailor who later became an important part of his life. He helped Crusoe in getting into the plantation business.