Which of the Following Statements Concerning Discouraged Workers in the Economy

Which of the following statements concerning discouraged workers in the economy is true?

A) They increase the size of the labour force,but do not affect the unemployment rate.
B) They reduce the size of the labour force,but do not affect the unemployment rate.
C) They may cause the official unemployment rate to understate the real amount of unemployment.
D) They may cause the official unemployment rate to overstate the real amount of unemployment.
E) They do not affect the size of the labour force,but do cause the unemployment rate to be higher than it would otherwise be.