Exp) Option b is the correct answer.

The power to include or exclude from the list any caste or tribe is conferred on the Parliament and the Parliament can undertake that exercise only by passing a legislation.

Statement 1 is incorrect. The criterion followed for specification of a community, as scheduled tribes are indications of primitive traits, distinctive culture, geographical isolation, shyness of contact with the community at large, and backwardness. This criterion is not spelt out in the Constitution but has become well established.

Statement 2 is correct. The first specification of Scheduled Tribes in relation to a particular State/ Union Territory is by a notified order of the President, after consultation with the State governments concerned. These orders can be modified subsequently only through an Act of Parliament.