| While on watch at sea, you notice the main lube oil pump suction vacuum has been increasing. To correct this you should __________ . |
| A) slightly open drain lines on each of the duplex suction strainers to decrease vacuum differential |
| B) back flush each of the duplex strainer baskets through the recirculating line |
| C) stop the main engine prior to removing suction strainer covers, if changing over to the standby strainer did not correct the condition |
| D) rotate the knife edge cleaning device handle one complete turn |
