The correct answer is D) placed in a fixed bracket when being used. In an open lifeboat, the lifeboat compass is typically placed in a fixed bracket when being used, as this helps to stabilize the compass and ensure its accurate readings. This is the standard procedure for securing the compass in an open lifeboat, as it prevents the compass from being moved or shifted during the boat's operation, which could otherwise affect its reliability. The other options are not correct because: A) the compass should not be clamped in a random position, as this could compromise its accuracy; B) the compass is not mounted in the center of the boat to eliminate deviation, as this is not a common practice; and C) the compass is not permanently mounted on the lifeboat's centerline, as it needs to be secured in a fixed bracket for proper use.