What does the law of increasing costs state?

a. that as the price of one good increases, the demand for that good will also increase
b. that if the demand for a good increases, supply will increase, causing price equilibrium
c. that if the supply of one good increases, the demand for that good will decrease, causing a shortage
d. that as factors of production shift from producing one good or service to another, the cost of producing the second good or service increases