When deployed, what effect do spoilers have on the aircraft?

Spoilers are designed primarily to reduce lift on an aircraft. When deployed, they create turbulence over the wing, which disrupts the smooth airflow that contributes to lift generation. This is particularly useful during landing, as it allows the aircraft to descend more steeply and slows it down by increasing drag while reducing lift. By decreasing lift, spoilers help to enhance the aircraft's ability to settle onto the runway safely and effectively.

The other options do not accurately describe the function of spoilers. For instance, increasing speed would not be a result of spoiler deployment, as their purpose is to enhance control and reduce speed during critical phases of flight, especially landing. Balancing weight is not a function of spoilers; rather, this relates more to the distribution and center of gravity in the aircraft. Lastly, spoilers have no role in enhancing cabin pressure, which is managed separately through the aircraft's pressurization systems.