Here's the reason for the correct sequence of statements in open market operations:

1. Central bank initiates the process by buying government bonds in the open market (Statement C).
2. To pay for these bonds, the central bank issues a check or pays the seller electronically (Statement B).
3. By purchasing government bonds, the central bank increases the total amount of reserves in the economy (Statement D).
4. As the reserves in the banking system increase, banks have more money available for lending and, in turn, create more money through the lending process. This leads to an increase in the money supply (Statement A).