Answer: (A) Air
Explanation:
Air transportation is one of the expensive transportation mode on the basis of per pound as pound is the unit of the weight.
Air transportation is one of the fastest mode of transportation now a days but the cost of air transportation is much expensive as compared to all the transportation facilities.
The air crafts and air planes most high for the construction and the common people cannot afford to use the air transportation facilities.
Therefore, Option (A) is correct.
