The radar control that reduces weak echoes out to a limited distance from the ship is the __________.

Correct Answer: Option B — sensitivity time control (sea-clutter control)

Sensitivity Time Control (STC), often labeled as Sea Clutter, automatically reduces the receiver gain for nearby targets. Since sea return is strongest near the vessel, STC suppresses these weak, close-range echoes while maintaining full sensitivity for distant targets, ensuring the PPI remains clear of clutter in the immediate vicinity of the ship.