Ascientist wants to determine the best light wavelength for growing plants. he grows plants in four test groups as shown in the table below. what, if anything, was wrong with the experiment?
a. he should only grow one plant in each group.
b. he should only change the wavelength of light for each group.
c. he should add a control group with a co2 level of zero ppm and a light intensity of zero percent.
d. there is nothing wrong with the experiment.