Correct Option
Disguised unemployment refers to a situation where more individuals are employed in a task than are actually required to produce the current output. In such a scenario, the marginal productivity of labour is zero. This means that if some of the workers are withdrawn from the activity, the total output remains unchanged. This phenomenon is commonly observed in the agricultural sector and informal economies where a large family may be working on a small plot of land, even though fewer members could achieve the same level of production.
Incorrect Options
Option (a): Disguised unemployment is not about a large number of people being openly unemployed. Instead, it describes a situation of underemployment or inefficient employment where people appear to be working but do not add to the total output.
Option (b): While the lack of alternative employment opportunities can contribute to the prevalence of disguised unemployment, it is not the defining characteristic of the concept itself. The core definition focuses on the productivity of the existing labour force.
Option (d): Low productivity of workers implies that their output per unit of input (time, effort) is below a desired or potential level. However, this is distinct from zero marginal productivity. Zero marginal productivity specifically means that an additional worker contributes nothing to the total output, which is the hallmark of disguised unemployment. Low productivity does not necessarily mean zero marginal productivity.