Take context from the input text and decide on the accurate relationship between 'Williams Companies' and 'natural gas' from the options provided.
Options: chairperson, manufacturer, original broadcaster, product/material produced

Within this article: Details on U.S. natural gas pipeline projects, including those from major companies such as Kinder Morgan Incorporated ( KMI ), TransCanada Corporation ( TRP ), Spectra Energy Corporation ( SE ) and Williams Companies ( WMB ).
product/material produced