When more and more workers are applied on the fixed land then the marginal productivity of additional worker will ............... to the total output.

Option 1 -> Initially marginal productivity may rise, but this is only in the early stages with optimal resource utilization.

Option 2 -> This would imply marginal productivity remains constant, which contradicts the law of diminishing returns.

Option 3 -> A vertical marginal productivity curve has no economic meaning in this context.

Option 4 -> As more workers are added to fixed land, each additional worker has less land to work with, causing marginal productivity to decline.

Hence, Option 4: Fall -> This follows the Law of Diminishing Marginal Returns. When a variable factor (labor) is continuously increased while keeping a fixed factor (land) constant, after a certain point, the marginal product of each additional unit of the variable factor declines. This happens because the fixed factor becomes overcrowded, leading to inefficiency. For example, if 10 workers on 1 acre produce well, adding the 20th or 30th worker will contribute progressively less to total output as there's insufficient land per worker. -> correct