Explanation:

- The correct answer is: Option 1 - Cash Reserve Ratio (CRR)

- Cash Reserve Ratio (CRR): It decides the minimum fraction of total deposits that banks must hold as reserves with the central bank. The deposit multiplier effect, or how many times initial deposits can be multiplied, is mainly governed by the CRR.

- Legal Reserve Ratio (LRR): This combines CRR and SLR and represents what banks must keep as reserves (both in cash and liquid assets), but the actual multiplier is determined by the reserve ratio (often called CRR in India's context).

- Statutory Liquidity Ratio (SLR): It’s the percentage of deposits banks must maintain in liquid assets like gold or government securities, not directly linked to the deposit multiplier.

- Bank Rate: It’s the rate at which banks borrow from the central bank, unrelated to deposit multiplication.