The correct answer is: d) All of the above.
Guwahati is well-connected by air, rail, and road. The city is served by Lokpriya Gopinath Bordoloi International Airport, which is the busiest airport in Northeast India. The airport has regular flights to major cities in India and neighboring countries. Guwahati is also well-connected by rail. The city is served by Guwahati Railway Station, which is one of the major railway stations in India. The station has regular trains to major cities in India. Guwahati is also well-connected by road. The city is connected to major cities in India by national highways and state highways. The city also has a well-developed public transportation system.