A study was conducted to measure the effectiveness of hypnotism in reducing pain. The measurements are centimeters on a pain scale before and after hypnosis. Assume that the paired sample data are simple random samples and that the differences have a distribution that is approximately normal. Construct a 95% confidence interval for the mean of the "before - after" differences. Does hypnotism appear to be effective in reducing pain? Before 8.9 1.2 6.2 12.8 8.8 10.4 3.9 0.8 After 6.1 2.1 7.7 8.5 8.5 6.1 3.6 2.2 ... Construct a 95% confidence interval for the mean of the "before - after" differences. |(Round to two decimal places as needed.) Does hypnotism appear to be effective in reducing pain? O A. Yes, because the confidence interval includes zero. B. Yes, because the confidence interval does not include and is entirely greater than zero. O C. No, because the confidence interval does not include and is entirely greater than zero. D. No, because the confidence interval includes zero.