What should a pilot verify before commencing an approach procedure?

The comprehensive preparation for any approach procedure is crucial for a successful and safe flight operation. Verifying that all navigation systems are operational ensures that the pilots have the necessary tools for guidance and can accurately follow the approach path. This includes checking navigational aids, such as GPS, VOR, or ILS systems, to confirm they are functioning correctly.

In addition to ensuring navigation systems are operational, confirming that the weather is suitable for the approach is equally important. Adverse weather conditions can significantly affect approach safety and procedures, such as low visibility or strong wind conditions that could challenge the approach stability.

Both of these aspects—functioning navigation systems and favorable weather conditions—are fundamental checks a pilot must undertake before beginning an approach. Addressing these factors together ensures that the pilot is fully prepared for the challenges of the approach, making this the correct answer.