Option 4: (A) - (III), (B) - (IV), (C) - (I), (D) - (II) -> Let's understand each term: Cash Reserve Ratio (CRR) is the percentage of deposits which commercial banks must keep as cash reserves with the Central Bank, matching with (III). Statutory Liquidity Ratio (SLR) refers to reserves that banks must maintain in liquid form (cash, gold, government securities) in the short term, matching with (IV). Lender of last resort is a function of the Central Bank of the country, which provides emergency liquidity to banks, matching with (I). Repo Rate is the interest rate at which money is lent by the Central Bank to commercial banks for short-term needs, matching with (II). These are key monetary policy instruments used by central banks to control money supply and liquidity in the economy. -> correct