Explanation:

Gram Panchayat:
- Gram Panchayat is the local self-government institution at the village level in India.
- It is responsible for the administration of the village and the implementation of various developmental programs and schemes.
- The Gram Panchayat consists of elected representatives called Panchayat members who are responsible for making decisions and implementing policies for the welfare of the village.

Gram Sabha:
- Gram Sabha is a general body consisting of all the adult members registered in the electoral rolls of a village.
- It is the primary unit of decision-making in the Panchayati Raj system.
- The Gram Sabha meets regularly to discuss and decide on various issues related to the village.
- It has the power to approve the annual development plans, monitor the implementation of government schemes, and ensure transparency and accountability in the functioning of the Gram Panchayat.

Secretary of the Gram Panchayat:
- The Secretary of the Gram Panchayat is an administrative officer appointed by the government.
- The Secretary plays a crucial role in the functioning of the Gram Panchayat.
- They are responsible for maintaining the records, preparing budgets, implementing government schemes, and assisting the Panchayat members in decision-making.
- The Secretary acts as a link between the Gram Panchayat and the higher levels of administration.

Secretary of the Gram Sabha:
- The Secretary of the Gram Panchayat also acts as the Secretary of the Gram Sabha.
- This means that the same person fulfills the role of the Secretary for both the Gram Panchayat and the Gram Sabha.
- As the Secretary of the Gram Sabha, they are responsible for organizing and conducting the meetings of the Gram Sabha.
- They assist the Gram Sabha members in preparing the agenda, recording the minutes, and implementing the decisions taken by the Gram Sabha.

Significance of the Secretary being the Secretary of the Gram Sabha:
- The Secretary being the Secretary of the Gram Sabha ensures smooth coordination and communication between the Gram Panchayat and the Gram Sabha.
- It helps in effective implementation of the decisions taken by the Gram Sabha at the grassroots level.
- The Secretary plays a crucial role in ensuring the participation of all members of the Gram Sabha in the decision-making process and promoting transparency and accountability in the functioning of the Gram Panchayat.

Therefore, the correct answer is option 'B' - Gram Sabha.

C