根据短文内容，从下面选项中选择恰当的选项填入文中空白处，使短文内容完整、通顺。每个选项只能用一次。
Jack is a successful businessman because he is kind and honest. He never lies to his partners and always keeps his promise. As a result, people like doing business with him and he has made many friends during his career（职业生涯）.
One cold October day, Mark, a man from outside town came up to Jack and wanted to do business with him. At the very beginning, Jack was not sure whether to work with him. However, Mark was so good at talking that Jack chose to believe him.
About three weeks later, Jack found Mark had cheated him. What was worse, he was terribly ill. People in the neighborhood heard the news and all wanted to help him. They went out of their way to support him with great encouragement. They even offered him plenty of money with little expectation in return. With the help of his neighbors and other business partners,
Whenever Jack is asked about the key to his success, he always smiles and replies, " "
A. He decided to work with Mark in the end.
B. Jack got his business up and running again.
C. He even thinks about others more than himself.
D. Honesty is the most important.
E. Jack lost a lot of money and his business was in trouble.
