Blackwater is wastewater that contains fecal matter and pathogens, such as from toilets. Greywater is wastewater that is less contaminated, such as from showers, sinks, and washing machines1. However, the classification of kitchen sink wastewater may vary depending on local codes and regulations. Some states and authorities consider kitchen sink wastewater as blackwater because it may contain food waste and germs123. Others consider it as greywater if it meets certain quality standards and is used for beneficial purposes, such as irrigation or toilet flushing45. A CIR (Credit Interpretation Request) is a process to seek clarification on a specific credit or prerequisite in a LEED rating system, but it does not change the definition of blackwater or greywater.
Greywater Reuse | WaterSense | US EPA4
Greywater - California Department of Water Resources5
What Is Greywater? What Is Blackwater? | HomeServe USA1
Grey Water / Reclaimed Water | University of Maryland Extension2
What is meant by the terms Gray water and black water3
Credit Interpretation Requests (CIRs) | U.S. Green Building Council

The Energy and Atmosphere (EA) category addresses the energy performance, efficiency, and renewable sources of buildings. One of the credits in this category is EA Credit: Enhanced Refrigerant Management, which aims to reduce the emissions of ozone-depleting substances and greenhouse gases from refrigeration and air-conditioning equipment. Refrigerants are substances that are used to transfer heat in cooling systems.
Some refrigerants have high global warming potential (GWP) and ozone depletion potential (ODP), which means they can contribute to climate change and damage the ozone layer if they leak or are improperly disposed of. Enhanced refrigerant management involves selecting refrigerants with low GWP and ODP, minimizing refrigerant charge size, and preventing or detecting leaks12. References: LEED v4 Green Associate Candidate Handbook1, LEED v4 BD+C Reference Guide2

The LEED for Schools rating system includes specific requirements not found in other BD+C categories:
"Minimum Acoustical Performance - Schools ONLY - EQp3 + EQc9... This prerequisite is for school projects only to provide a quiet environment to facilitate the teacher-to-student and student-to-student communication." This makes "Minimum Acoustic Performance" a required prerequisite for schools.

Water Efficiency is the only credit category that does not have a prerequisite in LEED v4 for Building Design and Construction. Prerequisites are the minimum requirements that all projects must meet to be eligible for LEED certification. They are mandatory and non-weighted, meaning they do not contribute to the project's score. The other credit categories have at least one prerequisite each, as shown in the table below:

References: LEED v4 Reference Guide for Building Design and Construction, p. 17 1; [LEED v4 BD+C Scorecard]

According to the LEED v4 Minimum Program Requirements (MPRs), there is no minimum required number of occupants or full-time equivalents (FTEs) for which a building must be designed to be considered eligible to pursue certification1. However, the project must serve at least one FTE, which is based on an 8-hour day2.
The other options are not part of the MPRs.
Minimum Program Requirements (MPRs) - U.S. Green Building Council1
LEED 101: MPRs (Minimum Program Requirements)2