845a8e7d_ption___MuOnline_Pentium_Tools__Why_to_edit_
[File Location] \Data\Local\ [File Name] ItemAddOption.bmd [Description] Stored configuration of Options for 380lvl Items, or Halloween and Cherry Blossoms event option or Partial charge option [Why to edit?] 
If you want to add more items options, I suggest to edit in server side ItemAddOption.txt file, and then to import to clients bmd file.
MuOnline Files Description - MuOnline Pentium Tools
Why to edit?