Explanation: Detecting small targets requires maximizing the energy reflected back to the receiver relative to the noise. A **long pulse width** allows the transmitter to radiate energy for a longer duration towards the target. This means more total electromagnetic energy reaches the target and, subsequently, more energy is potentially reflected back. **High output power** directly increases the amount of energy transmitted per unit of time. Combining a long pulse width with high output power ensures that the maximum possible energy is transmitted, significantly increasing the strength of the tiny reflected signal from a small target. This improved signal strength enhances the signal-to-noise ratio at the receiver, making the faint echo from a small target more detectable against background noise. Conversely, short pulses (Option A) contain less total energy per pulse, making small targets harder to detect, though they offer better range resolution. Specific frequency bands (Option B) have their own advantages, but the fundamental principle of transmitting sufficient energy (power and pulse width) is paramount for detecting inherently weak reflections from small objects.