Answer:
The correct answer is option A.
Step-by-step explanation:
The law of diminishing returns states that as we go on employing more and more unit of input while keeping other inputs constant, the return from each additional unit of input will go on declining.
This means that the output produced from each additional unit of input will go on declining.
Here, as capital is kept constant and labor is increased by a unit, the output at first increases by 5 units from 20 to 25. But later when input is again increased by a unit, the output increase by only 3 units from 25 to 28.
This shows the law of diminishing marginal returns where the marginal returns from a unit of labor is declining.