Earlier this year, $14.7 billion cap Equinix received its formal IRS REIT approval, eclipsing $9.4 billion Digital Realty Trust, Inc. (NYSE: DLR ) as the largest publicly traded data center REIT, calculated by market cap.
Take context from the input text and decide on the accurate relationship between 'Equinix' and 'data center' from the options provided.
Options: parent organization, product/material produced, creator, manufacturer