Spoilers 2, 3, and 4 can be extended in flight as?

Spoilers 2, 3, and 4 on the A320 are designed to operate as speedbrakes during flight. When deployed, they contribute to increasing drag, which helps to slow the aircraft down without needing to reduce engine power. This function is particularly useful for descent and approach phases of flight, allowing the pilot to manage airspeed and improve control without significantly impacting aircraft lift at low speeds.

The term "speedbrakes" specifically refers to the operational capacity of these spoilers to increase drag effectively. While they might also have some secondary effects that affect aerodynamic control, their primary design and function are to serve as speedbrakes. Understanding this function is critical for pilots when managing the aircraft's performance during various phases of flight, especially when preparing for landing or need to reduce altitude quickly.

This choice aligns directly with the operational characteristics of these spoilers, making it the correct answer to the question posed.