The correct answer is D. Change in the cost of inputs.
A change in the supply of a commodity along with same supply curve may occur due to a change in the cost of inputs. This is because the cost of inputs is a major factor in the production of a commodity. When the cost of inputs increases, the cost of production also increases. This makes it less profitable to produce the commodity, and so suppliers will produce less of it. As a result, the supply curve will shift to the left.
On the other hand, when the cost of inputs decreases, the cost of production also decreases. This makes it more profitable to produce the commodity, and so suppliers will produce more of it. As a result, the supply curve will shift to the right.
The other options are not correct because they do not directly affect the cost of production.
- A change in the price of the commodity will affect the demand for the commodity, but it will not directly affect the cost of production.
- A change in the prices of related goods will affect the demand for the commodity, but it will not directly affect the cost of production.
- A change in the future expectations of the price of the good will affect the demand for the commodity, but it will not directly affect the cost of production.