The term 'Intended Nationally Determined Contributions' is sometimes seen in the news in the context of

1. A

   Pledges made by the European countries to rehabilitate refugees from the war-affected Middle East

   European refugee pledges. INDCs are climate contribution texts under the UNFCCC, not a Middle East refugee facility. This letter is not the key.

2. B

   Plan of action outlined by the countries of the world to combat climate change

   Climate plan of action. Intended Nationally Determined Contributions were each Party’s pre-Paris 2015 outline of mitigation (and often adaptation and finance) toward the UNFCCC process. That stored letter is the official key.

3. C

   Capital contributed by the member countries in the establishment of Asian Infrastructure Investment Bank

   AIIB capital. Asian Infrastructure Investment Bank subscriptions are unrelated to INDCs. This letter is not the key.

4. D

   Plan of action outlined by the countries of the world regarding Sustainable Development Goals

   SDG action plans. The 2030 Agenda is a separate UN development frame. INDCs sit in the climate track, so this letter is not the key.

Summary. Official key is (b) the climate plan of action. Before the Paris Agreement, Parties filed INDCs; after ratification they became NDCs. They are not refugee, AIIB or SDG documents. Honour the stored letter (b).