The pairs provided are incorrect because the National Highways (NH) mentioned do not connect the cities as outlined. For instance, NH4 connects Mumbai and Pune, while NH6 connects Mumbai and Kolkata via Nagpur, and NH15 connects Jaisalmer to Ahmedabad, not Ahmedabad directly to Jodhpur. Understanding the actual routes of National Highways is crucial for UPSC aspirants, as it falls under infrastructure development and national connectivity, both important themes in Indian geography and planning. Correct identification of such highways is essential for questions related to logistics, transportation, and regional development in India.