Question

the passage below describes an experiment.
crown gall tumors on a rose stem
jodie grew roses for a flower shop. one day,
she noticed tumor-like growths on her rose
stems. she could tell that the plants had crown
gall disease, which is caused by a type of
bacteria. she knew that allicin, a chemical in
garlic, can kill bacteria. jodie wondered if
spraying her plants with garlic juice would
prevent more tumors from forming on her
plants. once a day, jodie sprayed garlic juice on
ten infected plants, sprayed a mixture of half
water and half garlic juice on ten other infected
plants, and left another ten infected plants
unsprayed. after one month, she compared the
number of new tumors on plants in the three
groups.

in this experiment, which were part of an experimental group?
the roses that were not sprayed
the roses sprayed with garlic juice

Explanation:

Experimental groups are the sets in an experiment that receive the variable being tested (here, garlic juice treatments). The unsprayed roses are the control group, while the groups exposed to garlic juice (full strength and diluted) are the experimental groups.

Answer:

the roses sprayed with garlic juice, the roses sprayed with a mixture of half water and half garlic juice