Which innovative retail-related requirement must be met for a building to achieve full 'Living Building Challenge' certification?

The architecture industry has been revolutionizing sustainable design practices through various certification systems. Among these, the Living Building Challenge represents one of the most rigorous sustainability standards in the architectural world. This poll tests your knowledge about this transformative retail-related certification that has changed how architectural products and materials are selected, sourced, and implemented in modern sustainable buildings.

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All building materials must be sourced from vendors within a designated radius (usually 500km) to reduce transportation impacts
The project must incorporate a 'Red List Free' materials strategy, refusing to use materials containing harmful chemicals commonly found in retail products
At least 75% of the building's retail spaces must offer only products that are certified carbon-neutral
The building must generate 150% of its energy needs through renewable sources and sell excess to local retailers