Which body of water's operation is controlled by the St Lawrence Seaway Development Corporation?

The St. Lawrence Seaway Development Corporation is responsible for the operation and maintenance of the St. Lawrence Seaway, which facilitates shipping access from the Atlantic Ocean to the Great Lakes, including Lake Ontario. This agency plays a critical role in managing the navigation system, ensuring that vessels can travel safely and efficiently through the locks and channels. Lake Ontario serves as the entry point to the Great Lakes for ships navigating the St. Lawrence River, and efficient operation of this waterway directly impacts the shipping and economic activities related to the lake.

The other lakes mentioned do not fall under the jurisdiction of the St. Lawrence Seaway Development Corporation. For instance, Lake Superior, Lake Erie, and Lake Michigan are managed by different regional authorities and do not interact with the St. Lawrence Seaway in the same manner as Lake Ontario. This makes Lake Ontario the correct answer, as it is integral to the operations overseen by the St. Lawrence Seaway Development Corporation.