Detailed Instructions: Given a sentence and two mentions from the text (arguments), indicate a phrase (a verb or noun phrase) that describes the relationship between the provided arguments.
Q: Sentence: 'Friedman LLC , a leading private equity firm based in San Francisco , announced today that Frank Zarb , most recently chairman and chief executive officer of the Nasdaq Stock Market , has joined the organization as a senior advisor and managing director .', Argument/Subject 1: 'llc', Argument/Subject 2: 'san francisco'
A:
be base in