The author uses the second paragraph to argue that the brain cannot be separated into independent modules. The thirds paragraph uses fMRI to challenge this general brain usage theory because fMRI show clear localization of metabolic activity in the brain. Paragraph four demonstrates that the clear localization of fMRI images is due to its usage of differential metabolic activity. The fMRI images only show the region that has the most pronounced metabolic activity by subtracting its excess from the baseline level occurring in other levels in the brain.
This shows that the brain is being used as a whole and that the fMRI does not disprove this. Essentially a rephrase of answer choice E.