Read the following passage and mark the letter (A, B, C or D) on your answer sheet to indicate the correct answer to each for the question from 43 to 50.

Charles Lindbergh was born in Detroit, Michigan, in 1902 but was raised on a farm in Minnesota, where his father was elected to the U.S. Congress in 1907. From then on, he spent his boyhood alternately in Washington, D.C. Detroit, and Little Falls, Minnesota. Because Lindbergh exhibited exceptional mechanical talent, in 1921 he was admitted to the University of Wisconsing to study engineering. However, the young man was seeking more challenging endeavors, and two years later he became a stunt pilot who performed feats at county fairs and public assemblies. This unusual and dangerous undertaking paid off handsomely in the sense that it allowed him to gain a diverse and well–rounded experience in aeronautics. He particularly delighted in what he called “wing–walking” and parachute jumping.

 After a year of training as a military cadet, Lindbergh completed his program at the Brooks and Kelly airfields at the top of his class and earned the rank of captain. Robertson Aircraft Corporation of St. Louis, Missouri, offered him employment as a mail pilot to run the routes between St. Louis and Chicago, and Lindbergh retained his position with the company until 1927. During this period, he set out to win the Raymond B. Orteig prize of $25,000 to be awarded to the first pilot to fly nonstop from New York to Paris. This ambition would irreversibly change his life and accord him a prominent place in the history of aviation.

 Embarking on the greatest adventure of his time, Lindbergh left Roosevelt Field at 7:52 A.M. on May 20, 1927, and landed at Le Bourget Field at 5:24 P.M. the next day. Fearing that he would be unknown when he arrived, Lindbergh carried letters of introduction to dignitaries in Paris, but when his plane came to a stop, he was overwhelmed by tremendous welcoming crowds. He was decorated in France, Great Britain, and Belgium, and President Coolidge sent a specially designated cruiser, the Memphis, to bring him back, His accomplishments in aeronautics brought him more medals and awards than had ever been received by any other person in private life. 

According to the passage, Lindbergh did not complete his degree because he