SHMessageBoxCheck

[DllImport("shlwapi.dll", CharSet = CharSet.Unicode)]
public static extern uint SHMessageBoxCheck(
   IntPtr hwnd,
   [MarshalAs(UnmanagedType.LPWStr)] string pszText,
   [MarshalAs(UnmanagedType.LPWStr)] string pszCaption,
   uint uType,
   int iDefault,
   [MarshalAs(UnmanagedType.LPWStr)] string pszRegVal
);

Microsoft documentation: Link