Explanation

Correct answer: (c) Creation of mini forests in urban areas

Developed by Japanese botanist Akira Miyawaki, this ecological-engineering technique plants dense, multi-tiered native saplings (canopy trees, sub-trees, shrubs, groundcovers) at high densities in compact urban spaces — producing a mature, self-sustaining micro-forest in 20-30 years instead of the ~200 years conventional forestry would take.