The correct answer is: a) Sarpanch.
A Sarpanch is the head of a Gram Panchayat in India. The Gram Panchayat is the lowest level of government in India and is responsible for local issues such as sanitation, water supply, and education. The Sarpanch is elected by the people of the Gram Panchayat and serves a five-year term.
The other options are incorrect. A Pradhan is the head of a Gram Panchayat in West Bengal. A Chairperson is the head of a Gram Panchayat in Tamil Nadu. A Zilla Adhyaksh is the head of a Zilla Parishad, which is a higher level of government than a Gram Panchayat.