Final answer:
The portion of Canada's drinking water supplied by groundwater aquifers is 30%.
Step-by-step explanation:
The portion of Canada's drinking water supplied by groundwater aquifers is d) 30%.
According to the Environmental Protection Agency (EPA), although the majority of community water systems in Canada are supplied by groundwater, more people are supplied year-round by community water systems that use surface water. The EPA states that 78% of community water systems are supplied by groundwater, while 68% of people are supplied by systems that use surface water.
Based on the information provided, the correct answer is option d) 30%.