Explanation: When a Search and Rescue Transponder (SART) is activated and interrogated by an X-band radar, it transmits a series of 12 sweeps. On the radar display, these sweeps appear as a line of 12 equally spaced dots extending outwards from the SART's actual position along its line of bearing. As the searching vessel approaches the SART (i.e., the distance to the SART *decreases*), the SART's signal strength received by the radar increases. This causes the individual dots on the display to broaden and elongate, forming increasingly longer arcs. When very close, these arcs can merge into continuous lines or even form concentric circles around the SART's true location. Therefore, option C correctly describes this phenomenon: the line of dots indicates the SART's position, and the dots become increasing arcs as the vessel closes the distance to the SART. Options A and C are identical and both represent the correct description. Option B is incorrect because the line of dots does not "rotate"; it remains on the SART's line of bearing. Option D is incorrect because the arcs become *increasing*, not decreasing, as the vessel approaches the SART.