At which point should a report be requested for operations at SFO/ELP?

A report should be requested at the entry point for operations at SFO/ELP because this is a critical phase during which the pilot is preparing to enter the controlled airspace and is likely to encounter various traffic and environmental conditions that could affect their approach and landing. The entry point serves as a transition area where pilots can provide pertinent information regarding their status, intentions, and any factors that might impact their approach to the airport.

Requesting a report at this juncture allows air traffic control to adequately manage incoming and outgoing traffic, ensuring safety and efficiency in operations. It enables controllers to be aware of the aircraft's position and intentions, which is vital for sequencing landings and takeoffs effectively while maintaining safe separation from other aircraft.

In contrast, the other options refer to different phases of flight where requesting a report may not provide the same level of situational awareness. For example, requesting a report at the runway threshold or before landing may not give enough time for air traffic control to respond or adjust traffic flows. Similarly, requesting a report after takeoff would generally be less useful for SFO/ELP operations, as the aircraft would already be in the air and past the point where air traffic control needs the information to manage arrivals or departures efficiently.