The correct answer is: Gram Panchayat, Panchayat Samiti, Zilla Parishad.
Gram Panchayat is the lowest tier of Panchayat Raj in Bihar. It is a self-governing body at the village level. It consists of a Sarpanch, who is the elected head of the Gram Panchayat, and a number of Panchas, who are elected representatives of the village. The Gram Panchayat is responsible for a variety of functions, including local planning, development, and welfare.
Panchayat Samiti is the intermediate tier of Panchayat Raj in Bihar. It is a federation of Gram Panchayats in a block. It consists of a President, who is elected by the Panchas of the constituent Gram Panchayats, and a number of Vice-Presidents, who are elected by the members of the Panchayat Samiti. The Panchayat Samiti is responsible for a variety of functions, including planning and implementation of development schemes, maintenance of law and order, and coordination of activities of the Gram Panchayats.
Zilla Parishad is the highest tier of Panchayat Raj in Bihar. It is a federation of Panchayat Samitis in a district. It consists of a President, who is elected by the members of the Zilla Parishad, and a number of Vice-Presidents, who are elected by the members of the Zilla Parishad. The Zilla Parishad is responsible for a variety of functions, including planning and implementation of development schemes, maintenance of law and order, and coordination of activities of the Panchayat Samitis.
The other options are incorrect because they do not represent the tiers of Panchayat Raj in Bihar.