Question

a passage about designing an experiment: kyoka testing peppers in the community garden... she found that different soil and nitrogen plants to grow faster. so, kyoka prepared nine pots for the pepper plants: in three pots she added only top soil; in three other pots she added top soil and one - half cup of nitrogen - based fertilizer; in the remaining three pots she added top soil and one cup of nitrogen - based fertilizer. she planted one pepper seed in each pot and observed how long it took for each plant to bear fruit. in this experiment, which were part of a control group? options: the pots with only top soil; the pots with top soil and one - half cup of fertilizer.

Explanation:

A control group in an experiment has no manipulated variable (fertilizer here). The pots with only top soil have no fertilizer, so they are the control to compare with pots having fertilizer.

Answer:

The pots with only top soil