I agree to Josiah. I even can't see the question...
However, from my understanding, of what you want to know:
1. OPTIONS method is used to ask the Webserver, which methods are supported. This is used quite often by MS Office, to find out if the server is supporting WebDAV for direct file access within office. As you can see from the header "User-Agent", the MS Office Discovery Protocol was the source of the request, what confirms my suspicion. Don't worry about the request. Just clear it or accept it - it's up to you.
2. The headline of your thread contains "via". Maybe you wan't to understand what is the VIA-Header for. The VIA-Header indicates, that the request was sent through a Proxy Server at the clients side. Just an information. But the sender should not to send this header due to avoid information discloure.
Hope this helps.
Greets,
svs