Solution:According to question the North-South corridor is the largest ongoing highway project in India. It is the second phase of the National Highway Development Project (NHDP). The correct option from North to South are Agra, Gwalior, Nagpur and Krishnagiri. Hence (a) is the correct answer.The National Highways Authority of India initiated the National Highway Development Program in 1998 to ease chronic capacity constraints by upgrading key arteries of the National Highways network. The project, which this validation is reviewing, was the third loan financed by the Asian Development Bank (ADB) for the multiyear lending program. The program upgraded into four lanes that are corridors connecting the major metropolitan cities of Delhi, Mumbai, Chennai, and Kolkata (known as the golden quadrilateral). The North-South corridor connects Srinagar to Kanyakumari (4,000 km), and the East-West corridor connects Silchar to Porbandar (3,300 km).
The North-South corridor is a 4,000 kilometers corridor that runs through NH 44 from Srinagar-Udhampur-Jammu-Jalandhar-Delhi-Agra-Gwalior-Jhansi-Narsinghpur-Lakhnadon-Nagpur-Hyderabad-Bengaluru-Salem-Madurai to Kanyakumari.
East-West Corridor includes 3,300 kilometers corridor via NH 27 from Porbandar-Rajkot-Samakhiali-Radhanpur-Kota-Jhansi- Kanpur-Lucknow-Ayodhya-Gorakhpur-Muzaffarpur-Darbhanga-Supaul-Purnia-Kishanganj-Galgalia-Bijni-Guwahati-Nagaon-Dabaka to Silchar.