Why is it important that an experiment include a control group? ...

[Hawke]

Why is it important that an experiment include a control group?
A) The control group is the group that the reseacher is in control of; it is the group in which the researcher predetermines the nature of the results.
B) The control group provides a reserve of experimental subjects.
C) A control group is required for the development of an "if; then" statement.
D) A control group assures that an experiment will be repeatable.
E) Without a control group, there is no basis for knowing if a particular result is due to the variable being tested or to some other factor.

[Celeste]

E