People travel most hope to arrive as soon as possible, so long-distance travel by plane or train, close more by car. Sometimes in order to enjoy the scenery on both sides of the river, there are also specialized tourist boats. Freight should be based on the nature of the goods, quantity, transportation distance, price, time and other circumstances, choose the mode of transportation. Generally speaking, valuable or urgently needed goods and the number is not large, more by air; easy to death, deterioration of live or fresh goods, short distance can be transported by highway, long distance and the number of available railroads on the special car; bulk bulky goods, long-distance transportation, as far as possible, the use of water transport or railroad transport. After the earthquake, China's National Earthquake Disaster Emergency Rescue Team departed from Beijing at 1:00 a.m. on April 21 to the Ya'an disaster area, the time is tight, the requirements of the speed of the choice of air transport is most appropriate.

The choice: C.

These are the most suitable choices for air transportation.