Answer:
Actually to make this short even though this question is from a while ago people who see this could use this so ima give my answer.
Part A:
The group of points labeled N is called a cluster. Point M is called an outlier. I'm not very sure about the presence of M myself so I'm just going to skip that sorry it's better than giving a wrong answer (even though its actually a pretty easy question lol)
Part B:
The more the students studied the higher their grade was or for the majority of the students atleast