Federalism and the 10th amendment work together--the 10th Amendment states that if something is not covered by the Constitution and there is no specific federal power, then the power goes to the state.
Federalism is the principle that government should be divided between a central power and regional powers. In the case of the 10th Amendment, if the central power doesn't have explicit power to do something then the states have the power to do so.
If you meant Denton Cooley, he was the first person to implant an artificial heart in 1969.
I believe the setting is in Barbados in the 1930's
"<span>d. high levels of both minerals and salinity" would be the best option, since without direct contact with larger bodies of water it's very hard for the minerals and salt to dissipate and "spread out".</span>