To say that two variables are confounded means that
A) They both vary at the same time.
B) As one variable changes, the other stays the same.
C) Both of the variables have been held constant.
D) Both variables are equally responsible for observed changes in the dependent variable.
Question 2
The only way to avoid confounding two variables is to make sure that
A) They vary independently of one another.
B) All variables are held constant.
C) All variables are allowed to vary freely.
D) All variables are properly labeled.