As per 101st Constitution Amendment Act, Article . . . . . . . . was inserted in the constitution.

The correct answer is: C. 246A

The 101st Constitution Amendment Act, 2019 inserted Article 246A into the Constitution of India. This article provides for the establishment of a National Commission for Backward Classes. The Commission will be responsible for investigating the conditions of socially and educationally backward classes and for making recommendations to the President for the amelioration of their condition.

The other options are incorrect because:

• Option A: Article 101B does not exist in the Constitution of India.
• Option B: Article 256A was inserted into the Constitution by the 92nd Constitution Amendment Act, 2003. It provides for the establishment of a National Commission for Minorities.
• Option D: Article 156B was inserted into the Constitution by the 93rd Constitution Amendment Act, 2005. It provides for the establishment of a National Commission for Women.