The concept of 'Green Infrastructure' is related to:

Correct answer: (c) Sustainable urban development

Explanation

Green infrastructure is a planned network of natural and semi-natural features in and around cities: parks, urban forests, wetlands, green roofs and walls, rain gardens and permeable pavements.

It is part of sustainable urban development: it soaks up stormwater and reduces flooding, cools urban heat islands, cleans the air and supports biodiversity, often at a lower cost than "grey" infrastructure such as concrete drains.