Final answer:
The beaver had a significant impact on Canadian history and exploration due to the fur trade demand for beaver hats, which fuelled trading and European settlement expansion. Option a is correct.
Step-by-step explanation:
The rodent that had a significant impact on the history and exploration of Canada is the beaver (Castor canadensis). The popularity of beaver hats in Europe during the fur trade era greatly influenced the demand for beaver pelts. This demand led to the establishment of trading relationships with Native Americans and the expansion of European exploration and settlements across Canada.
The beaver played a crucial role in shaping Canada's economy and environment, and its overhunting had various ecological repercussions, including the loss of beaver ponds and the subsequent impact on other species. Interestingly, other rodents, such as the groundhog and various species of squirrels, also have their own unique roles within their ecosystems, affecting vegetation and other wildlife populations.