The mineral alpha is added to bodies of fresh water to prevent the spread of certain freshwater parasites. The presence of those parasites threatens the health of the organisms living in rivers and streams throughout the country and imperils the freshwater commercial fishing industry. Alpha is currently mined only in the state of Blue. In order to raise needed revenue, Congress recently enacted a statute providing for the imposition of a $100 tax on each ton of alpha mined in the United States. Because it will raise the cost of alpha, this tax is likely to reduce the amount of alpha added to freshwater rivers and streams and, therefore, is likely to have an adverse effect on the interstate freshwater commercial fishing industry. The alpha producers in Blue have filed a lawsuit in federal court challenging this tax solely on constitutional grounds. Is this tax constitutional? 
No, because only producers in Blue will pay the tax and, therefore, it is not uniform among the states and denies alpha producers the equal protection of the laws.  No, because it is likely to have an adverse effect on the freshwater commercial fishing industry and Congress has a responsibility under the clause to protect, foster, and advance such interstate industries.  Yes, because the tax is a necessary and proper means of exercising federal authority over the navigable waters of the United States.  Yes, because the power of Congress to impose taxes is plenary, this tax does not contain any provisions extraneous to tax needs or purposes, and it is not barred by any prohibitory language in the Constitution. 