How do retractable landing gear affect an aircraft's performance?

Retractable landing gear significantly enhance an aircraft's performance by improving fuel efficiency through drag reduction. When the landing gear is extended, it creates additional aerodynamic drag, which can hinder the aircraft's performance and increase fuel consumption. By retracting the landing gear during flight, the aircraft presents a smoother profile to the oncoming airflow, minimizing drag and allowing for more streamlined flight.

This reduction in drag not only improves fuel efficiency but also can enhance overall speed and range capabilities. Pilots can achieve and maintain higher speeds more easily and efficiently when the landing gear is retracted, which is essential for optimal flight performance.

The other options do not reflect the primary impact of retractable landing gear on performance, as they either mischaracterize its effects or point out drawbacks that are not relevant to its main purpose.