In selecting a control group for research, which among the following is important in order to minimize the threat to internal validity? The control group a.            Must have the same demographic...

In selecting a control group for research, which among the following is important in order to minimize the threat to internal validity? The control group

a.            Must have the same demographic characteristics

b.            Should be exposed to the same history events

c.             Must benefit from the same maturation effect

d.            Should not suffer from regression artifact

e.            All the above