Under what condition can an aircraft exceed the established speed limits?

The correct answer relates to the scenario in which the minimum safe airspeed of an aircraft may exceed the established speed limits. This situation occurs in specific flight regimes where the aircraft must maintain a certain airspeed to avoid stalling or to ensure safe handling characteristics.

For example, during certain flight maneuvers, such as heavy turns or steep climbs, an aircraft's minimum safe airspeed might be higher than the prescribed speed limit. In these circumstances, the pilot is permitted to exceed the speed limit to ensure the aircraft remains in a safe operational envelope. This priority on safety is paramount in aviation, allowing pilots to maintain control and avoid hazardous situations that could arise from flying too slowly.

The other options do not provide valid conditions under which exceeding speed limits is acceptable. Descent, approach to an airport, or weather conditions typically do not grant pilots the discretion to exceed set speed regulations unless safety directly requires it, as explained in the context of minimum safe airspeed.