College athletes are known to have an average vertical jump of 18 inches with a standard deviation of 2.5 inches. After going through an intensive six-week jump training course a random sample of 50 athletes have an average vertical jump of 18.5 inches. Does this provide conclusive evidence that the jump training course is effective at raising a college athlete's vertical jump?

• A. No, the test value is larger than the critical value
• B. Yes, the test value is larger than the critical value
• C. Yes, the test value is smaller than the critical value
• D. No, the test value is smaller than the critical value