Gold an a supposed fountain of youth
Answer: I think it's B
Explanation: The mantle is the mostly-solid bulk of Earth's interior. So the mantle lies between Earth's dense, super-heated core and its thin outer layer, the crust.
I would choose between A and C because those make much more sense than the other problems.
If the highway is part of the federal highway system and the parks are part of the federal park system then it will be the federal government. If the roads and parks are part of the local and municipal systems like state, county and city roads and parks then that specific government is responsible.