What are the selectable flap positions for the aircraft?

The selectable flap positions for the aircraft are represented accurately in the correct choice. In many aircraft, the flap settings are designed to provide varying degrees of lift and drag, which are crucial for different phases of flight, particularly during takeoff and landing. The positions listed in the correct answer—0, 10, 20, and 30 degrees—allow for a range of configurations that can be used depending on the aircraft's requirements at various stages of flight.

For example, a 0-degree setting means the flaps are fully retracted, allowing for maximum speed and minimal drag during cruise flight. The intermediate positions (10, 20, and 30 degrees) provide incremental increases in lift, which can help lower the stall speed and improve control during low-speed maneuvers, such as approach and landing. Each position also impacts the aerodynamic characteristics of the aircraft differently, allowing pilots to optimize performance based on specific flight conditions.

The other options do not provide the typical configuration settings found in most general aviation or commercial aircraft, which is why they do not represent the correct selectable flap positions. Each aircraft model may have unique configurations, but common standards do exist for flap settings which are critical for flight safety and efficiency.