Answer: Purchasing new planes for a military campaign
Explanation:
As per the United States Constitution, there are certain roles that only the Federal government and not the state governments can assume and one of them is national defense.
It is therefore the responsibility of the the federal government to ensure that the nation's armed forces are well equipped to defend the country and that includes purchasing new planes. Federal revenue is needed to do this which is why federal taxes would most suitably go towards this.
The rest of the options fall under the authority of state and local authorities.
