From the table below, calculate the lower confidence interval estimate at a confidence level of 95%.

The historical data of Velvetta Inc., a healthcare products manufacturer, have shown that in a production process for filling bottles of shampoo, variance in the volume is constant; however, clogs in the filling machine often affect the mean volume. The historical standard deviation is 5 millilitres. In filling 250-millilitre bottles, a sample of 20 found a mean volume of 242 millilitres.

Velvetta Inc. Shampoo Production
Alpha Value	0.05
Standard Deviation	5
Sample Size	20
Sample Mean	242

A.

240.04

B.

239.81

C.

240.16

D.

239.49