The correct option is (d). none of the above is correct .For the "unemployed" category.
According to the Organization for Economic Co-operation and Development (OECD), unemployment is defined as those over a certain age (often 15) who are not now employed or self-employed but are nonetheless currently available for work during the reference period.
The number of unemployed people as a percentage of the labour force serves as a proxy for unemployment, which is expressed as the unemployment rate (the total number of people employed added to those unemployed).