SAP 4.0 SP2 Installation Question

CMS database and audit database (2008 version) were created on a different box. Prior to installtion, CMS ODBC and Audit ODBC connections were created.

When I got to the CMS database setup, I got three options to select before continue to the next step. What are these options mean?

Use Trusted Connection.

Show system database.

Reset existing database.

Thank you.