A lightbulb manufacturer wants to make sure the lightbulbs being produced give off the correct level of brightness. Brightness is measured using the unit of measurement known as a lumen. A worker randomly selects 100 lightbulbs and tests how bright they are. The mean brightness of this sample of lightbulbs is 450 lumens with a standard deviation of 6.8 lumens. The worker uses this data to construct the following 95% confidence interval: left parenthesis 448.67 comma 451.33 right parenthesis. Recommend a strategic decision for the manufacturer.

A. The manufacturer should increase the brightness level of these lightbulbs.
B. The manufacturer should decrease the brightness level of these lightbulbs.
C. The manufacturer should continue producing the lightbulbs without changes.
D. The manufacturer should use different electrical components to reduce the range of the confidence interval.