Answer
C. Parallel after discharge circuit.
This circuit has a single input neuron which stimulates several other neurons arranged in parallel. There is one output neuron and the impulses travelling in different parallel paths reach the output neuron at different times. This succession of arrivals results in a somewhat prolonged display called a burst or an after discharge. This kind of circuit is believed to be important in mathematical calculations.
Work Step by Step
A parallel after discharge circuit has one input neuron. The input from this neuron diverges to stimulate scores of other neurons arranged in several parallel pathways. These pathways then converge, and the impulses they carry arrive at the single output neuron at different times
This kind of circuit is said to be important in logical thinking and in mathematical calculations. It is also in operation in the withdrawal reflex, and in the after image seen after looking at a bright light and closing the eyes.