The correct answer is D because the historical baseline must be the average of the most recent three consecutive years of energy data available prior to the performance period1. Since the performance period calendar year is 2022, the most recent three consecutive years of energy data available are 2017, 2018 and
2019. The other options are incorrect because they either include years that are not consecutive or not prior to the performance period.
References: =
* LEED v4.1 O+M Reference Guide, page 139
* Guide to the LEED AP Operations and Maintenance (O+M) Exam, page 89
* LEED v4 AP O+M Mock Exam, page 85 ========================================= When a project is ineligible for an ENERGY STAR Rating and opts to document Energy and Atmosphere Prerequisite, Minimum Energy Performance by benchmarking against historical data, the selected baseline must be representative of the building's typical performance. The average of calendar years 2017, 2018, and
2019 serves as a relevant baseline because it provides recent, consecutive annual data that reflects the building's energy performance before any significant changes or improvements made for LEED certification.
This approach ensures that the performance period (in this case, the calendar year 2022) is compared against a stable and accurate representation of the building's typical energy use, allowing for a meaningful assessment of energy performance improvements.References:LEED v4 for Building Operations and Maintenance Guide,
U.S. Green Building Council.

The correct answer is D because the historical baseline must be the average of the most recent three consecutive years of energy data available prior to the performance period1. Since the performance period calendar year is 2022, the most recent three consecutive years of energy data available are 2017, 2018 and
2019. The other options are incorrect because they either include years that are not consecutive or not prior to the performance period.
References: =
* LEED v4.1 O+M Reference Guide, page 139
* Guide to the LEED AP Operations and Maintenance (O+M) Exam, page 89
* LEED v4 AP O+M Mock Exam, page 85 =========================================

Increasing the treatment levels of potable makeup water is an allowable method to increase cooling tower cycles of concentration. This is because treating the makeup water can help control the buildup of minerals and other impurities, allowing the system to operate more cycles before requiring blowdown.
References: The LEED v4.1 O+M reference guide and other LEED resources emphasize the importance of water treatment to manage cycles of concentration in cooling towers.Proper treatment helps maintain water quality and efficiency, which is crucial for achieving higher cycles of concentration without causing scale and corrosion problems1.