Which one the followings is known as transport city?

Kandla

The correct answer is Option (3) → Kandla

Transport Cities:They may be ports primarily engaged in export and import activities such as Kandla, Kochchi, Kozhikode, Vishakhapatnam, etc., or hubs of inland transport, such as Agra, Dhulia, Mughalsarai, Itarsi, Katni, etc.

Jharia and Digboi are examples of Mining Town.

Ambala is an example of Garrison/Cantonment town.