Respuesta :
Answer:
Its:
in an observational study, the researchers do not control treatment, and in an experiment, they do.
Step-by-step explanation:
It was D for you, but B for e :)
Answer:
Its:
in an observational study, the researchers do not control treatment, and in an experiment, they do.
Step-by-step explanation:
It was D for you, but B for e :)