Older water closets are replaced with Ultra low flush and Dual Flush fixtures.

• A. Standard flush toilets
• B. High-efficiency single-flush
• C. Conventional toilets
• D. Ultra low flush and Dual Flush fixtures

Answer: (D)

The main idea is using water-saving toilet fixtures when replacing older models. Ultra low flush and Dual Flush fixtures are designed to cut water use compared to traditional toilets. An ultra-low flush toilet typically uses a very small amount of water per flush, while a dual-flush toilet lets you choose a smaller flush for liquids and a larger flush for solids. This combination directly targets reducing water consumption with the flexibility to meet different flushing needs, which is why it’s the best fit for upgrading older water closets. The other descriptions describe less efficient or standard options that don’t emphasize the dual-flush efficiency or the ultra-low volume capability.