Option 1 -> This is the marginal product from the first unit of capital added (24-10=14), not the difference in change.
Option 2 -> This represents the difference between the two marginal products calculated.
Option 3 -> This is the total increase in product from initial to final (40-10=30), not the marginal product difference.
Option 4 -> This is the marginal product from the second unit of capital added (40-24=16), not the difference.
Hence, Option 2 -> First increase in capital: Marginal Product (MP1) = 24 - 10 = 14 units. Second increase in capital: Marginal Product (MP2) = 40 - 24 = 16 units. Difference in change in marginal product = MP2 - MP1 = 16 - 14 = 2 units. This shows the rate at which marginal product is increasing, indicating increasing returns to scale in this range. -> correct