Brain imaging techniques: differentiate MRI, fMRI, PET, and EEG.

• A. MRI shows structure; fMRI shows functional changes via BOLD signal; PET measures metabolic activity with tracers; EEG records electrical activity.
• B. MRI shows metabolic activity with tracers; fMRI measures structure; PET records electrical activity; EEG shows functional changes.
• C. MRI measures electrical activity; fMRI measures structure; PET shows blood flow; EEG shows metabolic changes.
• D. MRI shows structure; EEG measures metabolic activity; PET and fMRI measure electrical activity.

Answer: (C)