In the 10-20 international system of electrode placement, where is T3 located?

In the 10-20 international system of electrode placement, T3 is positioned 10% above the left preauricular point. This system is designed to standardize electrode placement for EEG and other neurophysiological measurements, ensuring consistency and comparability across different studies and practices.

The placement is implemented by using key anatomical landmarks: the nasion (the bridge of the nose) and the inion (the bump on the back of the skull) as well as points above the ears. For T3 specifically, being 10% above the left preauricular point aligns it within the temporal region of the skull, which corresponds to the left hemisphere's temporal lobe. This placement is critical for assessing functions and activity located in that area, such as auditory processing and language comprehension.

The other locations mentioned do not correspond to T3’s defined position within this standardized system, thus underscoring why option B accurately reflects the established method for electrode placement.