In studies of seed production, why is it important to assign plots of land to either the control group or treatment group at random?
a. it decreases the likelihood that the results of the study will be challenged.
b. it increases the chance that the study will be able to be scaled to a higher level.
c. it increases the likelihood that the treatment group will show a difference from the control group.
d. it decreases the likelihood that plots that receive a particular treatment share other characteristics that might influence seed production.