Answer :
group d, to be able to see what each does to the plant, you need to know what nothing does to it
Answer:
The correct answer will be option-D.
Explanation:
In a scientific experiment, the experiment is performed by dividing the sample into two groups- control and experimental.
In the control group, the samples are not treated with the variable being studied in the study that is it acts as an alternative to which the experimental samples in which the treatment is provided.
In the given question, since the effect of fertilizer on crops is being studied, therefore the fertilizer is the variable to be studied. So the crop with no fertilizer will be considered as a control group.
Thus, option-D is the correct answer.