Answer:
Neither species benefits.
Explanation:
For example, two different species that prey on the same or similar species of prey would be negatively effected by their competition for food, because there would be less food.
The only logical answer would be C. Unicellular, but the answers seem to be all wrong.
Essentially, a control variable is what is kept the same throughout the experiment, and it is not of primary concern in the experimental outcome. Any change in a control variable in an experiment would invalidate the correlation of dependent variables (DV) to the independent variable (IV), thus skewing the results.
