Is the fed responsible for central bank for country’s money?

Yes they are

Explanation:

Central banks are responsible for controlling the monetary policy of their countries. Essentially, this means that one of their key jobs is to manipulate the money supply in that country to meet its economic goals (such as market growth). (commonly referred to as "the Fed").

i would say b. research typically uses a variety of sources

the answer your looking for is c. : )