The correct pairs are 3 (Mahadeo Hills - Central India) and 4 (Mikir Hills - North-East India) because both these hills are well-documented geographical features that align with their respective regions. The Mahadeo Hills are part of the Central Indian highlands, while the Mikir Hills, located in Assam, are an extension of the broader Himalayan ranges and are characteristic of North-East India's geography. Understanding these geophysical features is crucial for UPSC Prelims, as it encompasses the study of regional geography and the interrelation of natural features, reflecting India's diverse topography and climatic conditions.