Which settings to endure that the Client Antivirus event is kept 1 year on the SEPM DB ?

Folks,

In SEPM 12.1.3 where can I set the SEP client event log to be kept by the server for one year ?

Shall I go to:

Option A: Admin--> Server --> localhost --> Edit database properties --> log settings.
Option B: Policies --> Virus & Spyware protection --> Antivirus and Spyware Policy (edit settings) --> Advanced Option --> Miscellaneous --> Log Handling --> Delete Logs older that .... text box ?

which one to set ? I'm confused between those two settings above.

how big is the file size going to be in the SQL Server back end database ?