I need help with this question. Having trouble understanding the correlations. Which of the following scenarios might be analyzed using a correlation?...

I need help with this question. Having trouble understanding the correlations.

Which of the following scenarios might be analyzed using a correlation?

a. The effectiveness of training A versus training B in raising skill level.

b. Minutes spent exercising per week and physical fitness score.

c. Income level and the number of visits to a financial planner.

d. Beer brand preference among college students.

I choose b for my answer.