Which sentence best concludes the passage?
The Wage Gap

Many theories try to explain why there is a large difference in the number of men and women working in areas such as engineering. U.S. researchers have also studied why women leave careers in science and engineering. According to an economist at McGill University, women leave such jobs because they are unhappy with the field. The study showed that women were not satisfied with the pay and the promotions.
More women engineers have left their jobs compared to any other profession in science. For many, the reason for quitting was not to raise a family. In fact, it was because 13 percent of these females were working in a field in which they did not specialize. About 60 percent of these women left the engineering field feeling discouraged.
The same gap between men and women was common in other fields as well. Most male-dominated fields saw a high female employee decline. More women felt unsure about their future and tended to quit compared to women pursuing other careers. ( blank)