Answer:
A.
Step-by-step explanation:
The central banks are those institution that manages and control nation's monetary policy. A central bank serves in providing funds to nation when commercial banks runs out of supply.
Therefore, the important role played by the central bank is that they control the interest rates charged by their governments. As the another function played by the central bank is to oversee that their members bank do not charge extra rates.
Thus option A is correct.