Which Missile seeker response requires the seeker to know the target's relative movement?

The correct response involves the understanding of how missile seekers function in relation to relative target movement. The Sector Attenuation seeker response requires knowledge of the target's movement because it is used to enhance the missile’s tracking capabilities within a specific sector by damping out the effects of interference and focusing the sensor's attention on the target’s movement.

In this context, knowing the relative movement of the target is essential for the seeker to adjust its focusing capabilities and maintain lock on the target amidst varying backgrounds and potential distractions. By understanding the target's trajectory and speed, the seeker can optimize its engagement tactics, ensuring a higher probability of a successful intercept.

The other options relate to different operational principles that do not necessitate a constant understanding of the target's movement in the same way, focusing instead on different aspects of missile guidance and tracking.