Concept:Disguised unemployment occurs when more people are employed than needed, so removing some does not reduce total output.
Explanation:In this situation, the marginal productivity of extra workers is zero, meaning they add nothing to production.
It is common in sectors like agriculture where family labour is shared, but many workers are not fully productive.
Such unemployment is hidden because people appear employed but are not contributing effectively.
Therefore, disguised unemployment directly implies zero marginal productivity of labour.
Answer:Option B (Zero marginal productivity of labour)