Find the 95% Confidence Interval for the Variance of the Lengths

Multiple Choice

Find the 95% confidence interval for the variance of the lengths of pipes if a sample of 16 pipes has a standard deviation of 12 inches.

A) $14.0 < \sigma ^ { 2 } < 10.0$
B) $8.9 < \sigma ^ { 2 } < 18.6$
C) $128.0 \sigma ^ { 2 } < 160.0$
D) $78.6 < \sigma ^ { 2 } < 344.9$