What is a primary focus of the ICAO according to its objectives?

The correct answer emphasizes the ICAO's commitment to enhancing global aviation safety and efficiency through the development of principles of international air navigation. The International Civil Aviation Organization (ICAO) works to establish comprehensive standards and recommended practices that govern how international air navigation should operate. This is crucial for ensuring safety, security, and regularity of international flight operations, contributing significantly to the seamless functioning of the global air transport system.

The other options, while relevant to the aviation field, do not align with the core objectives of the ICAO. Establishing flight ticket prices is generally handled by market forces rather than international regulation, developing codes for pilots falls under specific regulatory bodies rather than ICAO itself, and managing global airline routes is typically the responsibility of national authorities and agreements rather than a direct focus of the ICAO.