Which of these is an important waterway in Canada because it links the Great Lakes with the Atlantic Ocean?

A. Baffin Bay

B. Strait of Juan de Fuca

C. St. Lawrence Seaway

D. Hudson Strait

C. St. Lawrence Seaway

Explanation:

The two waterways are often jointly and simply referred to as the "St. Lawrence Seaway", since the Great Lakes, together with the St. Lawrence River, comprise a single navigable body of freshwater linking the Atlantic Ocean to the continental interior.

C. St. Lawrence Seaway

Explanation:

The seaway is named for the Saint Lawrence River, which flows from Lake Ontario to the Atlantic Ocean. Legally, the seaway extends from Montreal, Quebec, to Lake Erie and includes the Welland Canal.