If a commodity is provided free to the public by the Government, then

This question tests the core economic concept of **opportunity cost**, which is the value of the next best alternative foregone when a choice is made. While a commodity may be "free" for the consumer, the resources used to produce it (like labor and capital) are scarce and have alternative uses; therefore, the cost is not eliminated but transferred to the tax-paying public who fund the government's expenditure. Option (a) is incorrect because opportunity cost is only zero for non-scarce "free goods" like air, and option (d) is less precise than (c) because the government acts as an intermediary while the actual economic burden is borne by the taxpayers.