22D5 C
 You have been monitoring your 3-cm radar screen and a series of 12 concentric circles suddenly appears centered on the screen. What is the most likely cause of this situation?
A. There is a survival craft within 3 nm distance. 
B. There is a fault in the radar. 
C. Your own vessel's SART has been activated. 
D. Your own vessel's EPIRB homing beacon has been activated.
