A researcher summarizes her results of research into the amount of physical activity on severity of asthma symptoms. She states: 'the amount of physical activitysignificantly related to severity of asthmas symptoms, and reported anadjusted R²= .38. Which of the following would be the best interpretation of the variable in relation to these results?

A. 38% of the variation in severity symptoms is explained by amount of physical activity

B. Because only one predictor variable was used, it is not possible to calculate the correlation coefficient

C. Physical activity is not a significant predictor of severity of asthma symptoms in this study.

D. Knowing the level of physical activity does not significantly explain the severity of asthma symptoms