Could you help me?

Consider the following scenarios and explain why the correlation described need not imply that the first factor causes the second. Be explicit about the other factors that might be at play.

People who completed a graduate degree earn more than students who only completed a bachelor's degree.

Drinking diet soda is related to obesity and diabetes.

On average, students with relatively large student loans are less likely to default.

Students who repeat third grade score lower on fourth grade exams than those who do not.