Researchers are investigating the effect of pH level in water on the breeding habits of the moon jellyfish. As part of a laboratory experiment, they will randomly assign one of three treatments, low pH, medium pH, or high pH, to the water in the tanks that hold the jellyfish.
Which of the following is the best reason for the random assignment of a treatment level to an experimental unit?
A. Randomization tends to minimize the effects of uncontrolled variables, such as water temperature, so that such factors are not confounded with the treatment effects. B. Randomization will make up for improper experimental design, data collection, and analysis.
C. Randomization makes the analysis easier since the data can be entered into the computer in any order. D. Randomization is required by statistical consultants before they will analyze the experiment.
E. Randomization means that the experiment would not need to be replicated.