Which of the following individuals is the best example of a structurally unemployed worker?
选项：

A: a recent college graduate who has entered the labor force
B: an individual who has been laid off from his job because of a business cycle recession
C: an automobile worker who has lost her job because of an increase in automobile imports and does not have the skills currently needed by businesses
D: an individual who quits one job in the hope of finding a better job