Why the other options are wrong:

• Her neighbour recommended a new brand.: A neighbour's recommendation is not mentioned in the conversation.
• She wants a more modern design.: She does not mention wanting a more modern-looking unit.
• She is renovating her basement.: A basement renovation is not the reason she wants a new water heater.

Correct Answer: It heats water only when it is needed.

Why this is correct: The plumber explains that a tankless water heater heats water only when you need it, unlike a tank that stores hot water. This on-demand heating is the key feature that makes tankless systems different. It also means the family would never run out of hot water.

Why the other options are wrong:

• It stores fifty gallons of hot water.: Storing fifty gallons describes a tank heater, not a tankless unit.
• It requires no maintenance at all.: The plumber says tankless systems need annual flushing, so they do require some maintenance.
• It is cheaper to install than a tank.: The plumber says tankless units are more expensive to install, not cheaper.

Correct Answer: They save energy and take up less basement space.

Why this is correct: The plumber says tankless units save energy and take up less space, which is helpful because the homeowner's basement is tight. These are two practical benefits of going tankless. Energy savings and a smaller footprint are both real advantages.

Why the other options are wrong:

• They require no annual maintenance at all.: No annual maintenance is not accurate; the plumber says yearly flushing is needed.
• They can be installed in just a few hours.: The plumber says tankless installation takes a full day instead of half a day, so it is not faster.
• They work better with hard water than tank heaters.: The plumber mentions Ajax's hard water as a reason for annual flushing, not as a benefit of tankless systems.

Correct Answer: It requires more time to install.

Why this is correct: The plumber explains that installing a tankless system can take a full day, compared to half a day for a tank heater. This longer installation time is a drawback. It means more disruption to the household during the work.

Why the other options are wrong:

• It takes up more basement space.: Tankless units actually save space, not take up more of it.
• It may not provide enough hot water.: The plumber says tankless heats water on demand and does not run out. Insufficient hot-water supply is not given as the drawback; the stated drawback here is longer installation.
• It has a shorter lifespan.: The stated figures are usually ten to twelve years for a tank heater and up to twenty for tankless. A shorter tankless lifespan is not the drawback described.

Correct Answer: A high-efficiency fifty-gallon tank heater.

Why this is correct: The plumber recommends a high-efficiency fifty-gallon tank heater as the best option for the homeowner. the provider bases this on her budget and family size. It offers an easy replacement at a lower cost than going tankless.

Why the other options are wrong:

• Waiting another year to replace it.: The plumber does not suggest waiting another year; the provider says the current unit is near the end of its life.
• A standard tankless system.: The provider recommends a tank heater, not a tankless system.
• A basic forty-gallon tank heater.: The provider specifically says fifty gallons, not forty, for a family of four.

Correct Answer: The plumber will send a written estimate.

Why this is correct: At the end of the conversation, the plumber says the provider will send a written estimate later that day. This is the natural next step before the installation happens on Friday. The homeowner agrees to the plan and the plumber follows up with paperwork.

Why the other options are wrong:

• The plumber will inspect the basement again.: The plumber says he took a quick look at the current heater. Another basement inspection is not the stated next step.
• The woman will compare prices with other plumbers.: The homeowner agrees with the recommendation and does not mention comparing with other plumbers.
• The installation will be delayed for a week.: The plumber offers Friday-morning installation and the customer agrees. A delay for a week is not described; the immediate promised action is the written estimate.