According to the 'Focus on Neuroscience' Feature "Psychological Research Using

According to the 'Focus on Neuroscience' feature "Psychological Research Using Brain Imaging," which of the following statements is a potential limitation of brain imaging?

A) It is now considered unethical to use these techniques on humans; only animal studies are permitted.
B) Brain-imaging studies usually involve a small number of participants and tend to focus on simple aspects of behavior.
C) All brain-imaging studies use invasive procedures and radioactive substances and are potentially harmful to participants.
D) Because brain-imagining techniques use correlational methods, they cannot be used to determine precise associations between brain activity and psychological functions.