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).
Utilize the input text as a context reference, choose the right relationship between 'Berkshire Hathaway' and 'Warren Buffett' from the options.
Options: manufacturer, publisher, chairperson, founded by