Use the standard normal distribution or the t-distribution to construct a 90% confidence interval for the population mean. Justify your decision. If neither distribution can be used, explain why. Interpret the results. In a random sample of 50 people, the mean body mass index (BMI) was 28.5 and the standard deviation was 6. 19. Which distribution should be used to construct the confidence interval? Choose the correct answer below. nt O A. Use a normal distribution because the sample is random, the population is normal, and o is known. O B. Use a t-distribution because the sample is random, the population is normal, and o is unknown. DU O C. Use a normal distribution because the sample is random, n 2 30, and o is known. SS O D. Use a t-distribution because the sample is random, n > 30, and o is unknown. O E. Neither a normal distribution nor a t-distribution can be used because either the sample is not random, or n