Question

the passage below describes an experiment. franco worked in a restaurant that had a vegetable garden. part of his job was to care for the tomato plants. he had heard that pruning, or trimming, tomato plants can help tomatoes grow. he wondered if pruning would affect how well his tomato plants grew. franco chose 24 tomato plants that were similar in size. he pruned an equal number of branches from each of the first 12 plants. he left the other 12 plants unpruned. then, each week, franco weighed the tomatoes that he picked from each group of plants. complete the sentence. in this experiment, the pruned tomato plants were part of a control group an experimental group

Explanation:

In an experiment, the experimental group is the one that receives the treatment (in this case, pruning). The control group is left unchanged for comparison. Since the pruned tomato - plants received the treatment of pruning, they are part of the experimental group.

Answer:

an experimental group