Respuesta :
Actually both a) and b) are correct.
About A): the two groups should be identical (but not the same, i.e. have the same attributes), only the treatment of them - the independent variable should be different.
But the one option to choose is b: The control group is identical to each test group except for one variable. This is the independent variable.
About A): the two groups should be identical (but not the same, i.e. have the same attributes), only the treatment of them - the independent variable should be different.
But the one option to choose is b: The control group is identical to each test group except for one variable. This is the independent variable.
the answer for this would be b because of the independent variable