This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous System, Subject name: Physiology
Source of EEG 
Select and explain. 
A. A potential of pyramidal cells, B. A potential of ganglion cells, C. EPSP and IPSP of cortical cells which behave like dipoles, D. After potentials of parietal cortex
C: EPSP and IPSP of cortical cells which behave like dipoles
Answer: C: EPSP and IPSP of cortical cells which behave like dipoles 
Explanation: (C) EPSP and IPSP of cortical cells which behave like dipoles > The dendrites of the cortical cells are a forest of similarly oriented, densely packed units in the superficial layers of the cerebral cortex.> Propagated potentials can be generated in dendrites. In addition, recurrent axon collaterals end on dendrites in the superficial layers.> As excitatory and inhibitory endings on the dendrites of each cell become active, current flows into and out of these current sinks and sources from the rest of the