Final answer:
A CT scan is the most suitable brain imaging technique for locating bullet fragments before surgery, as it provides detailed images of the brain including bone and metal objects.
Step-by-step explanation:
Among the listed brain scan techniques, the one that would be most useful for locating bullet fragments before surgery is: b) Computed Tomography (CT) scan. CT scans can show a detailed cross-sectional image of the body including the bones, which makes it particularly useful for locating metal objects such as bullet fragments in the brain.
While Magnetic Resonance Imaging (MRI) generates detailed images, using an MRI to locate metallic materials (like bullet fragments) can be hazardous due to the powerful magnetic field. Positron Emission Tomography (PET) scans and Electroencephalogram (EEG) are not suitable for this purpose; PET scans are employed to observe metabolic processes and do not provide the necessary detail for locating bullet fragments while EEG records electrical activity and is not an imaging technique.