The value of r in correlation indicates both the magnitude and the direction of the relationship between two variables.
Magnitude: The absolute value of r tells us how strong the relationship is. A value closer to 1 or -1 indicates a stronger relationship, while a value closer to 0 indicates a weaker relationship.
Direction: The sign of r (positive or negative) tells us the direction of the relationship. A positive r indicates a positive correlation, meaning that as one variable increases, the other variable also increases. A negative r indicates a negative correlation, meaning that as one variable increases, the other variable decreases.
Therefore, the correct answer is c) both.