Explanation
Utilizing an existing community nature path connecting the building to surrounding buildings is an action that promotes pedestrian access to a project site. Pedestrian access is the ability of people to walk to and from a project site safely and comfortably. A community nature path is a type of pedestrian infrastructure that provides a pleasant and scenic route for walking, as well as environmental benefits such as habitat creation, stormwater management, and heat island reduction. The other options are not actions that promote pedestrian access to a project site. Placing a low speed limit in the parking lot around the building is an action that enhances pedestrian safety within the project site, but does not improve pedestrian access to the project site.
Providing shuttle access between the project site and a local transit center is an action that encourages alternative transportation, but does not promote pedestrian access to the project site. Designating parking spaces closest to the building for exclusive use by carpooling vehicles is an action that reduces vehicle trips and emissions, but does not promote pedestrian access to the project site. References: LEED Green Associate Candidate Handbook, page 30; USGBC, [Location & Transportation], page 3.

One of the things that LEED promotes by encouraging compact development is walkability. Compact development is a form of urban planning that aims to reduce sprawl and make more efficient use of land and resources by increasing density, diversity, and connectivity of land uses5. Compact development can enhance walkability by creating mixed-use neighborhoods that provide a variety of destinations within walking distance, such as shops, services, workplaces, schools, parks, and transit stops. Walkability can offer multiple benefits for the environment, health, economy, and social equity. For example, walkability can reduce greenhouse gas emissions and air pollution by replacing car trips with walking or transit; improve physical and mental health by increasing physical activity and reducing stress; support local businesses and generate tax revenues by increasing foot traffic and property values; and foster social cohesion and civic engagement by creating vibrant public spaces and enhancing accessibility for all6. Reference: Compact urban development6; LEED v4 BD+C Reference Guide, Location and Transportation, page 15

Explanation
The cradle-to-cradle approach to sustainable materials evaluates building materials from extraction to reuse, which means that the materials are considered as part of a continuous cycle of use and regeneration, rather than a linear process of consumption and disposal. The cradle-to-cradle approach aims to eliminate waste and pollution, conserve resources and energy, and create positive impacts for the environment and human health. The cradle-to-cradle approach is based on the principles of eco-effectiveness, which include designing products and systems that are safe and healthy for humans and nature, using renewable energy and clean water, celebrating diversity and creativity, and respecting social and environmental justice12. The cradle-to-cradle approach is also recognized and encouraged by LEED v4, which includes a credit for using products that have achieved Cradle to Cradle certification34.

ASHRAE sets standards used in LEED prerequisites: ASHRAE 90.1 for energy performance and ASHRAE 62.1 for indoor air quality. These standards guide projects in achieving minimum energy and air quality thresholds required for certification.