Which of the following statements best helps justify the inclusion of group 2 as one of the controls in the experiment?
A) I will show whether the changes observed in group 1 depend on the metabolic activity of Boll bacteria
B) will show whether the changes observed in group 1 depend on the type of plants used in the experiment.
C) It will show the average growth rate of seedings that are maintained in a nonsterile environment
D) I will show the changes that occur in the roots of seedlings following an infection by soll bacteria.