Legendary US investor Warren Buffett -- in a 2011 letter to shareholders of his Berkshire Hathaway investment group -- famously compared the entire world's gold stock of 170,000 metric tons, valued at $9.6 trillion (pile A) with another set of assets costing an equal amount (pile B).
Take context from the input text and decide on the accurate relationship between 'Warren Buffett' and 'Berkshire Hathaway' from the options provided.
Options: employer, member of, owner of, original broadcaster