Find the Confidence Interval Specified $\sigma$ = 31 Pounds

Multiple Choice

Find the confidence interval specified.
-49 packages are randomly selected from packages received by a parcel service. The sample has a mean weight of 11.7 pounds. Assume that $\sigma$ = 3.1 pounds. What is the 95% confidence interval for
The true mean weight, µ, of all packages received by the parcel service?

A) 10.6 to 12.8 pounds
B) 11.0 to 12.4 pounds
C) 10.7 to 12.7 pounds
D) 10.8 to 12.6 pounds