Flight spoilers assist in lateral control by being extended when:

Flight spoilers play a crucial role in enhancing lateral control during flight, particularly during maneuvers requiring a change in bank angle. When a pilot needs to initiate a roll to the left or right, spoilers are used in conjunction with ailerons to achieve a more effective response.

When the aileron on one wing is raised, it reduces lift on that wing, promoting a roll toward the opposite direction. By extending the spoilers on the same wing, drag is increased and lift is further decreased on that side. This combination effectively helps to improve roll control and allows for a smoother and quicker response to the pilot's commands. The increased drag on the outer wing also helps counteract the tendency for the aircraft to oppose banking with adverse yaw, enhancing overall lateral stability and control.

The other options, while related to aircraft control surfaces, do not accurately describe the role of spoilers in relation to aileron movement during lateral control maneuvers.