Explanation: Pulse-forming networks (PFNs) are specialized circuits designed to generate high-power, short-duration rectangular pulses, often used in radar modulators or particle accelerators. They achieve this by creating a ladder network comprising series inductors and shunt capacitors. This arrangement functions as an artificial transmission line. When charged and then discharged into a matched load, the energy stored within these L-C sections is released sequentially, maintaining a relatively constant voltage for a precise duration, thereby forming a rectangular pulse. This specific series L and shunt C configuration provides the characteristic impedance and propagation delay necessary for effective pulse shaping. Option A, with series capacitors and shunt inductors, would act more like a high-pass filter, which is not suitable for generating the desired pulse shape. Option C, a single resonant circuit, can store energy but lacks the distributed nature and sequential discharge capability required to form a sustained rectangular pulse of a specific duration.