Use the paired t-interval procedure to obtain the required confidence interval for the mean difference. Assume that the conditions and assumptions for inference are satisfied. Ten different families are tested for the number of gallons of water a day they use before and after viewing a conservation video. Construct a 90% confidence interval for the mean of the difference of the "before" minus the "after" times if the mean difference (after-before) was -4.8 and the standard deviation of the differences was 5.2451.

Before	33	33	38	33	35	35	40	40	40	31
After	34	28	25	28	35	33	31	28	35	33

Choose the best answer below:

A. (1.8,7.8)

B. (2.1,7.5)

C. (1.5,8.1)

D. (3.8,5.8)

E. (2.5,7.1)