Why the other options are wrong:

• Her family has grown recently.: Her family size is mentioned later, but it is not the reason she needs a replacement.
• She wants to qualify for a rebate.: Qualifying for a rebate is not why she called the plumber.
• She wants to lower her gas bill.: Lowering her gas bill is not given as the main reason for the replacement.

Correct Answer: It can provide continuous hot water.

Why this is correct: The plumber says tankless systems provide continuous hot water, so the family will not run out during back-to-back showers. This is a key advantage over tank heaters.

Why the other options are wrong:

• It is cheaper to install than a tank.: Tankless units are more expensive to install, not cheaper.
• It can be installed in under three hours.: Installation of a tankless system usually takes a full day, not under three hours.
• It requires less maintenance each year.: Tankless units need an annual flush, so they do not require less maintenance.

Correct Answer: The need to upgrade the electrical panel.

Why this is correct: The plumber says the woman's electrical panel is only 100 amps. For some tankless models, she would need an upgrade, which adds cost to the installation.

Why the other options are wrong:

• The lack of available rebates.: Rebates are described as sometimes available depending on model and timing. The stated extra cost is an electrical upgrade for some tankless models.
• The size of the water tank.: The size of the water tank is not mentioned as a factor for tankless cost.
• The age of the gas lines.: The age of the gas lines is not discussed as a cost issue.

Correct Answer: They should be flushed once a year.

Why this is correct: The plumber says tankless units need an annual flush, especially with Ajax water. This means they should be flushed once a year for proper maintenance.

Why the other options are wrong:

• They are maintained only when problems occur.: Maintenance is not limited to only when problems happen - it is a regular yearly task.
• They are flushed every few years.: The plumber says annually, not every few years.
• They do not need regular servicing.: The plumber clearly states that regular servicing is needed.

Correct Answer: It avoids electrical upgrades and can be installed quickly.

Why this is correct: The plumber says a high-efficiency tank heater can be done quickly and does not require electrical work. These two factors match the woman's time pressure and panel limitations.

Why the other options are wrong:

• It is more energy-efficient in the long term.: Tank heaters are described as less efficient overall, not more.
• It qualifies for a larger rebate.: A larger rebate for tank heaters is not mentioned.
• It lasts longer than a tankless unit.: Tank heaters last 10 to 12 years, which is shorter than a tankless unit's 20 years.

Correct Answer: The installation will take place the next day.

Why this is correct: The woman agrees to the tank heater and the plumber says installation can be scheduled for tomorrow morning. Next-day installation is proposed, rather than confirmed as completed or inevitable.

Why the other options are wrong:

• The woman will apply for a rebate.: Applying for a rebate is not mentioned as the next step.
• The plumber will inspect the electrical panel.: The plumber does not say the provider will inspect the electrical panel - the tank heater avoids that need.
• The woman will compare prices with another company.: The woman does not mention comparing prices with another company.