The Effect of Different Lighting Levels on Productivity Is Evaluated

Multiple Choice

The effect of different lighting levels on productivity is evaluated using a designed experiment.Two hundred office workers who have the same basic job assignments are randomly selected to participate.Each worker is randomly assigned a different lighting level at his or her desk.Ambient (background) lighting is held constant for all workers.A benchmark of productivity is recorded for each worker.In this study,the sample is best described as:

A) 200 office workers.
B) the different lighting levels.
C) the amount of productivity.
D) all office workers with similar job assignments.