Many people got As and Bs. When a neuron fires a small electrical spark jumps the gap between the axon and the dendrite. Information enters and leaves the neuron through the axon.
Electricity plays no role in neural transmission process.
However, test analysis statistics confirm that this question is a valid one. This analysis indicates that most of the students who did well on the exam, overall, got this question correct, whereas most of the poorer performing students got this question incorrect. The question's content was also closely reviewed during the class sessions, as well. The analysis indicates that the high scoring students tended to get this question correct, and that the middle and low scorers missed it. Smell is the only sensory system that is not routed through the thalamus before it projects to the cortex.