How can rescue personnel detect that a SART is transmitting in the immediate vicinity?（）

A. The SART's blips on the PPI will begin arcing and eventually become concentric circles
B. The DSC unit will react to the SART's signal and respond with the two-tone alarm
C. The SART can provide an approximate location to within a two nautical mile radius，per IMO standards
D. The SART signal appears as a target which comes and goes; the effect of heavy swells on a SART