Refer to the input text as context and select the correct relationship between 'Equinix' and 'data center' from the available options.
Options: product/material produced, creator, parent organization, manufacturer

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.
product/material produced