Final answer:
The correct answer is d) counterfeiting schemes, as infrastructure projects are supported by legitimate financial sources like state legislatures, the federal government, and European investors, not illegal activities.
Step-by-step explanation:
Financial support for infrastructure projects historically came from a variety of sources, but not from counterfeiting schemes. This illicit activity would not be considered a legitimate or legal source of funding for such projects. State legislatures (state governments), the federal government, and even European investors played roles in funding. For example, government agencies have been known to borrow money to raise funds for the purpose of building roads or mass transit. Sources such as selling war bonds, implementing an income tax, and securing foreign loans have also been methods for raising funds for large governmental projects. However, counterfeiting is a criminal endeavor that governments would not engage in or endorse as a means to finance infrastructure.