What Is the 95% Confidence Interval for the Gila River $\pm$

Multiple Choice

What is the 95% confidence interval for the Gila River sample of loach minnows given: mm,s = 6.2 mm,n = 50,and critical value of t = 2.01.

A) 56.2 mm + 1.77 mm
B) 56.2 mm $\pm$ 1.77 mm
C) 56.2 mm - 2.26 mm
D) 56.2 mm $\pm$ 0.25 mm
E) 56.2 mm + 0.25 mm