How can making an experiment single-blind or double-blind help?
A. If an experiment is blinded, the sample will be more representative of the population.
B. If an experiment is blinded, then differences between the control group and the treatment group are exaggerated.
C. If an experiment is blinded, then the sample can be less representative of the population and the data can still be used to make inferences about the population.
D. If an experiment is blinded, then any effect arising from psychological factors should affect all groups equally.