Concept:The fastest means of transport is the one that covers the greatest distance in the least time.Explanation:Air transport moves at much higher speeds than road, rail, or water transport.It travels through the sky without facing ground obstacles such as traffic or rough terrain.This allows it to cover long distances in a very short period.It is also comfortable and efficient for passengers and goods.Therefore, among the given options, air is the fastest means of transportation.Answer:B. air