Regarding the effects of coaching on standardized test scores, which of the following statements is most representative of current research?A. Coaching can lead to 100-point gains if the quality of coaching is high.B. Coaching is not likely to lead to 100-point gains if student motivation is high.C. The best predictor of increased test scores could be "number of times tested" and not "coaching." D. The best predictor of increased test scores could be "coaching quality" and not "student motivation."