Which event marked the beginning of the modern airline industry?
a. the wrights' first flight at kitty hawk in 1903
b. the u. s. post office's examination in 1908 of the feasibility of air mail service
c. lindbergh's flight to paris in 1927
d. the use of airplanes for mail transport

The correct answer is D. The use of airplanes for mail transport.

Explanation:

Passenger transportation services began to expand through the mail business and at the same time they began to prosper in important markets.

Since the establishment of this kind of service, airplanes became faster, bigger, and they have had improvements in terms of fuel-efficient. However, the technological improvements in the airline industry have decreased, but there are still some innovations that could be applied.

Passengers prefer the use of airplanes because they can travel long distances in less time and because the airlines usually offer competitive prices.  

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