‘Gadgil Committee Report’ and ‘Kasturirangan Committee Report’, sometimes seen in the news, are related to

The correct answer is D, Protection of Western Ghats. The Western Ghats Ecology Expert Panel, chaired by Prof. Madhav Gadgil, reported in 2011. It recommended treating most of the range as ecologically sensitive and restricting mining, big dams, thermal power and new construction. The High Level Working Group under Dr. K. Kasturirangan reported in 2013. It proposed a smaller ecologically sensitive area after consulting state governments.

Why the others fail:

• A) Constitutional reforms: these are environmental expert reports, not constitutional ones.
• B) Ganga Action Plan: a river-cleaning scheme launched in 1985 for the Ganga, unrelated to either committee.
• C) Linking of rivers: this belongs to the river-interlinking debate, such as the National Perspective Plan and the NWDA proposals, not these reports.

The core concept is ecologically sensitive areas and the Western Ghats as a biodiversity hotspot and UNESCO World Heritage Site since 2012. For Mains, this sits under GS-III on environment versus development and the livelihood concerns of local communities. Note that the final ESA boundaries have remained contested and delayed, so check the latest status before citing it as settled.

Trap: aspirants remember the names Gadgil and Kasturirangan as river or constitutional committees and guess by association. Anchor both reports to the Western Ghats.