【单选题】

Copernicus was born in Torun, Poland, on February 19,1473. Little is known about his early life except that his father died when he was 10.An uncle adopted him, his two sisters, and his brother. The uncle saw to it that the two boys received a good education.Copernicus went to the University ofCracow. There he studied such subjects as Latin, mathematics, and astronomy. It was probably at that time that he changed his Polish name, Niklas Koppernigk, to the Latin form of NicolausCopernicus. In 1496Copernicus went to Italy, where he spent the next 10 years studying at various universities.

InCopernicus’ time people still believed that al] things—the sun, the stars, and the planets moved around the earth. It was an old belief that few men had ever questioneD、Aristotle had based his theory of astronomy on this belief.Because theChurch had long been the center of learning, the theory was also linked to religious beliefs.
In 1506Copernicus returned to his homelanD、
A、few years later he began to work for theChurch.All those yearsCopernicus carried on his work in astronomy. He had just the most basic equipment and ,like other scientists of his day, made observations with only his eyes. Still ,using mathematics and logic,Copernicus worked out a different theory, which held that the planets went around the sun.
Copernicus did not announce his ideas. He did not want to make trouble.But he could not hide the scientific truth. So he talked about his theory with his friends, who strongly advised him to have his work publisheD、His great book, On the Revolutions of the HeavenlyBodies, appeared at the very end of his life.Copernicus saw the first copy on the day he died, May 24,1543.
The writer of the passage wants us to know that ______.
A、Copernicus did not tell about his discovery until the day of his death
B．for many yearsCopernicus dared to do nothing openly against theChurch
C．pushed by his friendsCopernicus decided to write a book in May 1543
D．shortly before he got back to PolandCopernicus started to work for theChurch