The correct answer is (a) Odisha.
As per the 2011 census, the percentage of Scheduled Tribe population in Odisha was 22.8%, followed by Madhya Pradesh (21.0%), Chhattisgarh (19.6%), Rajasthan (12.8%), and Jharkhand (12.6%).
Scheduled Tribes are indigenous peoples who are considered to be socially and economically backward. They are listed in the Constitution of India and are entitled to special privileges, such as reservation in education and employment.
Odisha has the highest percentage of Scheduled Tribe population because it is home to a large number of tribal groups, such as the Santhals, Mundas, Oraons, and Gonds. These groups have a long history of living in the state and have developed their own unique cultures and traditions.
The Scheduled Tribes of Odisha are facing a number of challenges, such as poverty, illiteracy, and lack of access to basic amenities. However, there are also a number of initiatives being taken by the government and civil society organizations to improve their lives.