Which of the following societies acts as an implementation arm of the National Ganga River Basin Authority?
A) National Mission for Clean Ganga
B) National Mission for Clean Ganga
C) National Mission for Cleaning Ganga
D) None of the above

Hint: National Ganga River Basin Authority (NGRBA) functions under the water resource ministry of India. This authority finances, plans, implements, monitors, and coordinates the issues with the Ganges river. The mission of the organisation is to protect the Ganges river from pollution or overuse.

Complete answer:
National Mission for Clean Ganga (NMCG) acts as an implementation arm of National Ganga River Basin Authority (NGRBA). It was constituted under the provisions of the Environmental Protection Act (EPA), 1986. It was registered on 12th August 2011 under the Societies Registration Act 1860.

The Objectives of NMCG are: 
(a) ensuring effective abatement of pollution and conservation of the river Ganga and
(b) maintaining environmental flows into the river Ganga ensuring water quality and environmentally sustainable development.

Some of the measures taken by NGRBA to protect river Ganga from pollution and to conserve the river in keeping with sustainable developmental needs are:
-Augmentation of sewerage infrastructure.
-Catchment area treatment.
-Protection of floodplains.
-Creating public awareness.
-Investigation and research with problems of environmental pollution.
-Promotion of water conservation practices including recycling and reuse of water, rainwater harvesting and decentralised sewage treatment systems.

Thus, the correct answer is option A (National Mission for Clean Ganga).

Note: The NGRBA is supported by the state level authorities such as State Ganga River Conservation Authorities (SGRCAs) in five Ganga basin States which are chaired by the chief ministers of the respective states. The five states of SGRCAs are Uttarakhand, Uttar Pradesh, Bihar, Jharkhand, and West Bengal, among others. Under NGRBA programme, projects worth Rs.4 Crore have been sanctioned upto 31st March 2014.