Correct option is D. 2 only
The prestigious Gold Standard Foundation
(GSF) certification has been awarded to the Delhi
Metro Rail Corporation (DMRC), for efficient
usage of energy, on 2 February, 2014. DMRC has
become the first ever Railway system in the world
with GSF certification standard. In 2008, DMRC
had also become the first Railway project in the
world to be registered by the UN under the Clean
Development Mechanism (CDM).