Answer:
The correct answer is option b.
Explanation:
A central bank is the central monetary authority in a country. It performs the functions of managing currency, money supply, controlling the commercial banks, etc. For instance, the Federal reserve bank in the US, the Reserve bank of India, the Bank of Spain, etc.
There are several roles played by a central bank.
Though guaranteeing the savings of its citizens is not a function of the central bank.