Explanation
A Renewable Energy Certificate (REC) is a tradable commodity that represents proof that one unit of electricity was generated from a renewable energy source. RECs are used to track and trade renewable energy in the open market, providing an economic incentive for renewable energy generation. References: LEED Green Associate Candidate Handbook, U.S. Green Building Council resources

Explanation
The best way to prevent a building's indoor pollutant(s) is to eliminate or control pollutants at the source.
Indoor pollutants are substances or particles that can adversely affect the indoor air quality (IAQ) of a building and the health, comfort, and productivity of the occupants. Indoor pollutants can originate from various sources, such as building materials, furnishings, cleaning products, combustion appliances, outdoor air, or occupant activities. Eliminating or controlling pollutants at the source can prevent them from entering or spreading in the indoor environment, which can reduce the exposure and risk for the occupants. Some examples of source control strategies are: using low-emitting materials, installing local exhaust ventilation, sealing combustion appliances, implementing green cleaning practices, and prohibiting smoking13. References: LEED v4 Green Associate Candidate Handbook1, EPA's Indoor Air Quality3

Explanation
Selecting native plants to provide habitat for local fauna is a strategy that a design team should consider in order to decrease the impact of a new construction project. Native plants are plants that have evolved in a specific region and have adapted to the local climate and soil conditions. Native plants can offer many benefits for the environment, such as:
Reducing water use and runoff by requiring less irrigation and fertilization Enhancing biodiversity and ecosystem services by supporting native wildlife and pollinators Improving air quality and mitigating climate change by sequestering carbon and reducing greenhouse gas emissions Increasing soil health and stability by preventing erosion and improving infiltration Creating a sense of place and cultural identity by reflecting the natural heritage of the region The other options are not strategies that would decrease the impact of a new construction project. Maximizing views of the existing wetland may improve occupant satisfaction, but it does not necessarily reduce the environmental footprint of the project. Locating the project in an existing office park with ample parking may reduce land use and transportation impacts, but it may also increase heat island effect and stormwater runoff.
Increasing the project's footprint to maximize roof space for a solar array may increase renewable energy generation, but it may also increase site disturbance, material use, and energy demand. References: : Native Plants