The correct answer is option 'A', Panchayat Samiti.

Panchayat System in India:
The Panchayat system in India is a three-tier system of local self-government at the village, intermediate, and district levels. It is a decentralized form of governance that aims to involve local communities in decision-making processes and ensure the efficient delivery of services to the rural population.

First Tier - Gram Panchayat:
At the village level, the Gram Panchayat is the primary unit of the Panchayat system. It is headed by the Sarpanch, who is elected by the members of the Gram Sabha (village assembly). The Gram Panchayat is responsible for various local matters like infrastructure development, sanitation, healthcare, education, etc., within the village.

Second Tier - Panchayat Samiti:
The second tier of the Panchayat system is headed by the Panchayat Samiti. The Panchayat Samiti is also known as the Block Panchayat or Mandal Panchayat. It is an intermediate level of local self-government that covers a group of villages within a specified area. The Panchayat Samiti consists of elected representatives from the Gram Panchayats falling within its jurisdiction.

Functions of Panchayat Samiti:
1. Planning and Development: The Panchayat Samiti is responsible for planning and implementing development programs and schemes in the block area. It prepares plans and budgets for the overall development of the block and ensures their effective execution.

2. Coordination and Supervision: The Panchayat Samiti coordinates the activities of the Gram Panchayats within its jurisdiction. It provides guidance, support, and supervision to the Gram Panchayats to ensure the proper implementation of government policies and programs at the grassroots level.

3. Resource Mobilization: The Panchayat Samiti plays a crucial role in mobilizing resources for the development of the block. It identifies potential sources of funding, explores opportunities for collaboration with government agencies and NGOs, and leverages funds for various development projects.

4. Service Delivery: The Panchayat Samiti is responsible for providing essential services like healthcare, education, sanitation, water supply, etc., in the block area. It ensures the effective delivery of these services by coordinating with relevant departments and monitoring their implementation.

5. Dispute Resolution: The Panchayat Samiti also serves as a platform for resolving disputes and grievances at the block level. It acts as a mediator between the Gram Panchayats and helps in resolving conflicts arising due to various issues.

Conclusion:
The Panchayat Samiti, as the second tier of the Panchayat system, plays a crucial role in the decentralized governance structure of India. It acts as a bridge between the Gram Panchayats and the district administration, ensuring effective planning, coordination, and implementation of development programs at the block level. By empowering local communities and involving them in decision-making processes, the Panchayat system aims to address the specific needs and aspirations of the rural population.