Answer:
The groups received the Independent variable.
Step-by-step explanation:
In any experiment or research. There are two main variables, Independent variable and the dependent variable.
A variable is any entity that has quantity or quality that changes.
The independent variable is the variable that a scientist can change or manipulate and has a direct effect on the results of an experiment.
The dependent variable is the variable that is measured following a change in the independent variable.
Therefore, the group was given the independent variable since that is the variable the researcher could control and it will affect the results of the experiment.