Marina Exam 2017: Which signal is sounded ONLY by a vessel in sight of another and NOT in or near an area of restricted visibility?

Marina Exam 2017

Which signal is sounded ONLY by a vessel in sight of another and NOT in or near an area of restricted visibility? 

A. One short blast 
B. One short, one prolonged, and one short blast 
C. One prolonged blast 
D. Four short blasts 


Answer:  A. One short blast