Suppose the Official Rate of Unemployment Reported by Statistics Canada

Suppose the official rate of unemployment reported by Statistics Canada is 7.2%.One reason this is likely to be an understatement of the amount of "true" unemployment is that

A) the official rate is a measure of gross flows into and out of unemployment rather than net flows.
B) discouraged workers who have given up searching for a job,but would take one if offered,are not included.
C) the official rate is a measure of net flows into and out of unemployment rather than gross flows.
D) Statistics Canada does not have a good measure of the numbers of people entering the labour force.
E) seasonal workers are not included at all in the official data.