Read the following lines from "The Early History of the Airplane":

"The first flight lasted only 12 seconds, a flight very modest compared with that of birds, but it was nevertheless, the first in the history of the world in which a machine carrying a man had raised itself by its own power into the air in free flight, had sailed forward on a level course without reduction of speed, and had finally landed without being wrecked."

Select the correct summary statement.

A. The Wright brothers flew.
B. The Wright brothers reached their goal of creating the first self-propelled flying machine.
C. The Wright brothers share key ideas about flight.
D. The Wright brothers flew for twelve seconds without interruption.