Explanation:

The Nature Solutions Finance Hub for Asia and the Pacific is an initiative aimed at promoting sustainable finance solutions in the region. Here's an overview of the entities listed:

- Option 1: The Asian Development Bank (ADB)

- Correct Answer: ADB launched the Nature Solutions Finance Hub to address environmental challenges in Asia and the Pacific.

- Option 2: The Asian Infrastructure Investment Bank (AIIB)

- This bank focuses on infrastructure development but did not launch this specific hub.

- Option 3: The New Development Bank (NDB)

- Known for funding BRICS nations’ projects, but not associated with this particular initiative.

- Option 4: The International Bank for Reconstruction and Development (IBRD)

- Part of the World Bank, involved in wider development financing, but not specific to this hub.