RISKS are MAKING people migrate to other countries, which in turn introduced a new CATEGORY of migrants, "climate refugees".From the passage, we can infer that a new PROBLEM occurred regarding the protection and recognization of these climate refugees in the countries to which they migrate.These climate refugees are yet to get recognization under international laws, and hence their protection hangs in the middle.Also, the climate migrates should get recognized in their own respective countries so that their problems can be addressed and solved better in the first place.From the above lines, we can conclude that - Relation between climate change and migration is not yet properly understood.Hence, option 4 is the correct choice.