Twenty different statistics students are randomly selected. For each of​ them, their body temperature ​(​C) is measured and their head circumference​ (cm) is measured. If it is found that r​0, does that indicate that there is no association between these two​ variables? Choose the correct answer below. A. ​No, because if r​0, the variables are in a perfect linear relationship. B. ​No, because while there is no linear​ correlation, there may be a relationship that is not linear. C. ​No, because r does not measure the strength of the​ relationship, only its direction. D. ​Yes, because if r​0, the variables are completely unrelated.