B. everything should remain the same between experimental groups
Explanation:
The control group, in one experiment, is characterized by individuals who will not receive the factor being tested in the experiment, but will also be evaluated at the same time points as the subjects in the intervention group. For example, if you have bean plants and want to do an experiment where you will evaluate the effectiveness of a fertilizer on bean plants, you will apply fertilizer on 9 bean plants while one plant will be maintained without fertilizing it. However all plants will be treated the same (except for fertilizer application) and will be evaluated in the same way. The fertilizer is the factor that is being tested in the experiment, the plant that did not receive it is the control group.
In primary succession there is no presence of soil or the soil cannot support life in secondary succession there is a presence of soil in which it can support life
