Which of the following is true about using air carriers as a transportation mode when shipping products?

A) Air carriers are the most cost-effective way to ship non-perishable goods over short distances.
B) Air carriers are the slowest and least reliable modes of transport.
C) Air carriers provide in-transit services such as the processing of goods en route.
D) Air carriers are ideal when time is short and speed is needed.
E) Air carriers are a specialized means of shipping chemicals from sources to markets.