Explanation:

- The National Biodiversity Authority (NBA) was established to implement India's Biological Diversity Act of 2002.

- It functions as a statutory autonomous body under the Ministry of Environment, Forest and Climate Change, Government of India.

- Option 3: 2003 – This is the correct year when the NBA was established to regulate and secure equitable sharing of benefits arising out of the use of biological resources.

- Option 1: 2006 – This year is not related to the establishment of the NBA.

- Option 2: 2000 – This predates the enactment of the Biological Diversity Act, which led to the authority's formation.

- Option 4: 2010 – This is also not related to the establishment of the NBA.