(a) Promotion of commercial farming in arid and semi-arid areas

(b) Development of gardens using genetically modified flora 

(c) Creation of mini forests in urban areas

(d)  Harvesting wind energy on coastal areas and on sea surfaces

12. Ans: c

Explanation:

Miyawaki Method: Named after Japanese botanist Akira Miyawaki, this method involves planting two to four different types of indigenous trees within every square metre. In this method, the trees become self-sustaining and they grow to their full length within three years.

The methodology was developed in the 1970s, with the basic objective to densify green cover within a small parcel of land. Unlike commercial forestry, in Miyawaki Forestry,  only native varieties of plants are selected in specific ratios and sequences, creating multilayer, maintenance-free forests, and 100 percent self-sustainable ecosystems.  

Miyawaki uses only local species. The forests blend with the local ecosystem, last longer, and can exist in urban spaces.

Hence, option c is correct.

Read: Previous Year UPSC Environment Questions (PYQs) With Explanation 2022