Utilize the input text as a context reference, choose the right relationship between 'Berkshire Hathaway' and 'Warren Buffett' from the options.
Options: currency, founded by, position held, director/manager

For example, two notable value investors operate businesses that fall into this category -- Tom Gayner at Markel and Warren Buffett at Berkshire Hathaway ( NYSE:BRK-A ) ( NYSE:BRK-B ) .
director/manager