Explanation:

- NABARD:

- NABARD, or the National Bank for Agriculture and Rural Development, is indeed the apex body that coordinates the activities of all financial institutions in the rural financial system.

- It was established to provide credit and develop policies for agriculture and rural development.

- Plays a critical role in sustainable rural prosperity.

- SHG:

- SHG stands for Self-Help Group.

- SHGs are small voluntary groups formed to promote savings among members and facilitate collective financial resource management.

- They don't serve as an apex body for financial coordination.

- Agricultural Marketing:

- This refers to all those activities which involve the supply of farm inputs to the farmers and movement of agricultural products from the farms to the consumers.

- It does not function as a coordinating body for financial activities.

- All of the above:

- Incorrect, as the functions of SHGs and Agricultural Marketing do not align with the role of coordinating financial institutions.