The correct pairs from the list are 1 and 3 only. Catalonia is indeed an autonomous community in Spain, known for its distinct culture and ongoing movement for independence. Mindanao, in the Philippines, is the second-largest island and has a significant Muslim population, which has led to historical tensions and calls for autonomy or independence. In contrast, Crimea is a region in Ukraine, not Hungary, and Oromia belongs to Ethiopia, not Nigeria. Understanding the geopolitical context of these regions is crucial for UPSC Prelims, as it emphasizes the importance of regional identities and conflicts in international relations.