Which of the following is NOT a safety question before a flight?

The correct choice, which identifies a question that is not specifically about safety before a flight, is focused on the pilot's individual qualifications rather than immediate operational safety concerns. The completion of flight training is an important aspect of a pilot's readiness to operate an aircraft; however, it does not address the safety of the particular flight being undertaken at that moment.

On the other hand, the other options directly relate to safety considerations necessary to assess before a flight. Inquiries about other air services declining due to weather help understand the current weather conditions impacting flight safety. Questions about technical issues with the aircraft pertain to the condition and readiness of the aircraft, which is critical for safe operation. Additionally, asking about other aircraft en route to the scene is vital for ensuring situational awareness and avoiding potential collisions.

Thus, while completing flight training is essential for ensuring that a pilot is qualified, it does not fall within the immediate safety-related questions to be asked before a specific flight commences.