Question 4 of 10 4.0 Points A survey of a random sample of 300 grocery shoppers in Kimberley found that the mean value of their grocery purchases was R78. Assume that the population standard deviation of grocery purchase values in R21. The 95% confidence interval for the mean grocery purchases is O A. (80.38; 75.62) . O B. (78.01; 89.38) . O C. (75.62; 80.38) . O D. (76.01; 81.13) . O E. (74.87; 81.13)