What is the appropriate Z or T value used in the interval (16 boats-8 painted with Brand A and other 8 painting in Brand B-the 95% confidence

What is the appropriate Z or T value used in the interval (16 boats-8 painted with Brand A and other 8 painting in Brand B-the 95% confidence interval for the true mean for Brand A minus the true mean for Brand B is (-5.3, 2.7)

A) 2.145

B) 1.960

C) 2.306

D) 2.365

E) None of values are correct