In Contrast to a PET Scan, the FMRI Technique

In contrast to a PET scan, the fMRI technique

A) requires an injection of a radioactive chemical.
B) provides more precise information when measuring a series of events in the brain.
C) is more accurate in determining what a person is thinking, for instance, whether the thoughts are pleasant or unpleasant.
D) involves placing electrodes on a person's scalp.