In your opinion which of the following is more important:

1. Velocity of money (V) or the money supply (M) for level of inflation (P)?

2. Opportunity cost or transaction cost in Baumol-Tobin model?

3. Liquidity ratio or required cash reserve ratio for commercial banks?

4. Line of credit or bank overdraft facility if you are a commercial business?

5. Letter of credit or pre-payment by trade financing service (if you are the seller)