Final answer:
Special purpose governments, such as local school districts, engage in one specific type of service, which is true. They exist to address specific public service needs more efficiently than broader governmental bodies. The necessary and proper clause generally expands, rather than limits, the powers of the national government.
Step-by-step explanation:
The statement that special purpose governments are engaged in only one governmental type activity is true. These are special districts with functions tailored to specific services, such as local school districts, and are often established in heavily populated areas to manage workload that county and city governments may not be able to handle alone. This is to address the unique requirements of certain public services that may not be as efficiently managed by larger, general-purpose governments.
Additionally, various aspects of government financing and functions were mentioned in the student's question. For instance, it is true that federal spending has grown substantially in recent decades, and a majority of federal revenue comes from personal income taxes. In contrast, foreign aid, despite common misconceptions, constitutes only a small fraction of federal spending. And contrary to the question's assertion, the necessary and proper clause has generally been interpreted as expanding the power of the national government, making the statement that it limits national government power false.