A sample size must be determined for estimating a population mean given that the confidence level is 95% and the desired margin of error is 0.23. The largest value in the population is thought to be 15 and the smallest value is thought to be 7. Complete parts a and b below. a. Calculate the sample size required to estimate the population mean using a generously large sample size. (Hint: Use the range/4 option.) The sample size required is Round up to the nearest whole number as needed.) b. If a conservatively small sample size is desired, calculate the required sample size. (Hint: Use the range/6 option.) Discuss why the answers in parts a and b are different. Select the correct choice below and fill in the answer box within your choice. (Round up to the nearest whole number.) 。A. The sample size required is This sample size is larger than the sample size in part a because it is found using a smaller estimate of the population standard deviation. O B. The sample size required is This sample size is smaller than the sample size in part a because it is found using a smaller estimate of the population standard deviation OC. The sample size required is.This sample size is smaller than the sample size in part a because it is found using a larger estimate of the population standard deviation. O D. The sample size required is This sample size is larger than the sample size in part a because it is found using a larger estimate of the population standard deviation.