The correct answer is A) removing hatch covers. On Great Lakes bulk ore vessels, an "Iron Deckhand" is a specialized crew member who assists in the physical tasks of opening and closing the large hatch covers over the cargo holds. This involves operating the machinery and manually maneuvering the heavy hatch covers to allow for loading and unloading of the bulk cargo, such as iron ore. The other options are incorrect, as an Iron Deckhand would not be responsible for unloading the cargo, steering the vessel, or mooring the ship to the dock, which are duties typically handled by other crew members with different specializations.