What must you do before descending from 10,000' to 8,000' if you were assigned a speed of 300 KIAS or greater?

Before descending from 10,000 feet to 8,000 feet while being assigned a speed of 300 KIAS or greater, it is necessary to slow to 250 KIAS. This requirement is in place to ensure safety and compliance with regulations, as the altitude of 10,000 feet marks a transition point where specific speed limits come into effect. The FAA mandates that all aircraft must not exceed 250 KIAS below 10,000 feet in order to manage air traffic effectively and reduce the risk of collisions and maintain orderly flight operations. Thus, when descending from 10,000 feet to 8,000 feet, complying with this speed restriction is essential.

The other responses may imply actions that do not align with regulatory requirements or best practices in air traffic control, making it necessary to adhere to the specified speed constraint of 250 KIAS during this descent phase.