Explanation: For short-range applications, a **narrow pulse width** is crucial. A narrow pulse provides superior range resolution, allowing the system to distinguish between closely spaced objects. It also minimizes the minimum detectable range because the receiver can recover and begin listening for echoes sooner after the shorter transmission. A **fast repetition rate** is also ideal for short ranges. Since echoes from nearby objects return very quickly, a fast repetition rate ensures that the next pulse is transmitted soon after, leading to more frequent updates and a higher probability of detecting targets. This high rate doesn't create ambiguity problems for short-range targets because the echoes return well before the next pulse would create a false-range indication. Conversely, wide pulses would reduce range resolution and increase the minimum detectable range, while slow repetition rates would be inefficient, providing fewer updates and potentially missing targets.