What is created by the action of speed brakes?

The action of speed brakes results in the creation of additional drag on the aircraft, which can be interpreted as an increase in weight from the perspective of the aircraft's handling and performance. When speed brakes are deployed, they disrupt the airflow over the wings and body of the aircraft, increasing aerodynamic drag. This increased drag does not contribute to lift or thrust; rather, it slows down the aircraft and aids in descent or deceleration.

In the context of the other options, speed brakes do not create lift as they are intended to reduce speed and enhance control, not improve the lifting capability of the wings. They do not contribute to increased speed; in fact, their primary purpose is to help reduce the aircraft's speed. Similarly, they do not generate engine thrust, which is a function of the aircraft's engines. Hence, the deployment of speed brakes leads to a scenario where the aircraft experiences increased drag, analogous to an additional load impacting its aerodynamic efficiency.