单项选择题If your asphalt barge has operated more than 12 months in saltwater in the 24 month period since it was last dry-docked,when is it required to be hauled out again? ()
A.12 months since last dry-docking
B.18 months since last dry-docking
C.24 months since last dry-docking
D.36 months since last dry-docking