A.
As a student’s class attendance decreases, the student’s overall grade remains the same
B.
As the number of hours a person exercises decreases, the weight of that person increases
C.
As the number of miles driven increases, the amount of the gasoline in the tank decreases
D.
As the amount of water plant receives increases, the growth rate of the plant increase.
Answer Explanation
Correlation of two variables falls into:
Positive correlation: an increase in one variable causes another variable to increase
Negative correlation: an increase in one variable causes another one to decrease
No correlation: a change in one variable does not cause any response in another variable.
From the given choices
Option a is no correlation
Option b is a negative correlation
Option c is a negative correlation
Option d is a positive correlation
Thus, the correct statement is a.