Why Might the Official Unemployment Rate Be an Understatement of Actual

Why might the official unemployment rate be an understatement of actual levels?

A) Because both part-time workers and discouraged workers are included.
B) Because both part-time workers as well as those collecting EI but not actively seeking work are included.
C) Because people working in the underground economy are not included.
D) Because part-time workers are considered employed,and discouraged workers are not considered unemployed.
E) Because those not actively seeking work while collecting EI benefits and those in the underground economy are included.