Do high-efficiency toilets require water to flush?

High-efficiency toilets are designed to use significantly less water per flush compared to traditional toilets, making option A the accurate choice. Typically, high-efficiency toilets use about 1.28 gallons per flush or less, whereas standard toilets might use about 1.6 gallons or more.

Option B states that high-efficiency toilets require no water to flush, which is not accurate. All toilets, including high-efficiency models, require some amount of water to function effectively. Therefore, the idea that they can operate without water is incorrect.

The fact that high-efficiency toilets minimize water usage is a key selling point, particularly in efforts to conserve water resources. However, it's important to clarify that while they utilize less water, they still fundamentally require it to flush waste effectively.

Options C and D present incorrect characterizations of high-efficiency toilets in how they utilize water or what they might use instead. So, focusing on the concept of efficiency and water conservation is essential for understanding the benefits of these toilets in managing water resources.