when a factor is controlled by setting it to three levels, the particular factor is of no interest to the researcher. True or false and why? A. The statement is false because a factor that is controlled and set to a particular value is a factor of interest to the researcher. B. The statement is true. C. The statement is false because a factor that is controlled and set at various levels is a factor of interest to the researcher. D. The statement is false because a factor that is controlled must be set to two levels.