Explanation:

Recently, the three-judge bench of Supreme Court referred to a five-judge Constitution  Bench of pleas challenging the central government’s decision to grant 10 % quota to Economically Weaker Sections (EWSs) in jobs and admissions in the general category.

• The economic reservation was introduced in the Constitution by amending Articles 15 and 16 and adding clauses empowering the state governments to provide reservation on the basis of economic backwardness.
• The validity of the Constitutional Amendment was challenged, saying the 50% quota limit was part of the Basic Structure of the Constitution.
• A three-judge bench had refused to stay the implementation of the Constitution (103rd Amendment) Act, which provides the 10% quota.

How centre defends this move?

• The Centre had argued that it was every State’s prerogative to provide 10% economic reservation in State government jobs and admissions in State-run education institutions. Whether or not to provide reservation to the economically weaker section (EWS) of the society for appointment in State government jobs and for admission to State government educational institutions, as per provisions of the newly inserted Articles 15(6) and 16(6) of the Constitution, is to be decided by the State government concerned.
• The government also argued that under Article 46 of the Constitution, part of Directive Principles of State Policy, it has a duty to protect the interests of economically weaker sections.
• Countering the claims that the amendment violates the Indra Sawhney principle, the government relied on a 2008 ruling— Ashok Kumar Thakur v Union of India, in which the SC upheld the 27% quota for OBCs. The argument is that the court accepted that the definition of OBCs was not made on the sole criterion of caste but a mix of caste and economic factors, to prove that there need not a sole criterion for according reservation.

Hence option 3rd is correct.