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.
In the context of the input sentence, determine the relationship between 'Equinix' and 'data center'.
Options: manufacturer, creator, parent organization, product/material produced