In the context of the input sentence, determine the relationship between 'Phosagro' and 'MOSCOW'.
Options: platform, director/manager, headquarters location, owned by

MOSCOW Aug 3 Russian fertiliser producer Phosagro said on Monday that its agent Citigroup Global Markets Deutschland had reopened a facility that allows conversions between Phosagro's global depositary receipts (GDRs) and ordinary shares.
headquarters location