Final answer:
The Great Lakes and St Lawrence Lowlands are relatively small compared to the entire landmass of Canada, occupying less than 2% of the area. The correct answer is option B).
Step-by-step explanation:
The Great Lakes and St Lawrence Lowlands are significant features in Canada's geophysical landscape. However, they do not comprise a large percentage of Canada's landmass. The correct answer to what percentage of Canada's landmass the Great Lakes and St Lawrence Lowlands contain is B) <2%