What do slats do when deployed during takeoff and landing?

When slats are deployed during takeoff and landing, they primarily serve to increase lift. Slats are devices located on the leading edge of the wing that enhance the airflow over the wing at lower speeds. When an aircraft is taking off or landing, it is operating at lower speeds, which can make it more susceptible to stalling due to reduced lift.

By deploying slats, the aircraft modifies the wing's shape, allowing it to maintain lift at these critical phases of flight. Increased lift is crucial for safe takeoff and landing, enabling the aircraft to operate effectively even at slower speeds and higher angles of attack. This enhanced aerodynamic performance is key to ensuring that the aircraft can support its weight and maintain controlled flight during these phases.

While the other options mentioned have their significance in aviation, they do not specifically describe the primary function of slats during takeoff and landing. For instance, while slats can contribute to improved overall flight efficiency, their main role is to generate lift under conditions where the aircraft needs it most.