Final answer:
The St. Lawrence River and Seaway would most likely be used to help southeastern Canada trade with countries across the Atlantic Ocean.
Step-by-step explanation:
The St. Lawrence River and Seaway would most likely be used to help southeastern Canada trade with countries across the Atlantic Ocean.
The St. Lawrence River is a major waterway that connects the Great Lakes to the Atlantic Ocean. It provides a direct route for ships to travel from Canada to countries across the Atlantic.
The St. Lawrence Seaway is a system of locks and canals that allows ships to navigate through the St. Lawrence River. It provides a way for large cargo ships to transport goods between southeastern Canada and countries across the Atlantic.