Utilize the input text as a context reference, choose the right relationship between 'Berkshire Hathaway' and 'Warren Buffett' from the options.
Options: developer, legal form, chief executive officer, distribution format

View photo A Berkshire Hathaway shareholder poses with a likeness of Berkshire CEO Warren Buffett at the shareholder's shopping day in Omaha, Nebraska May 1, 2015.
chief executive officer