What is the relationship between Network Rail and London in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

These included SE1, Cable and Crucifix Lane, which were all based in the arches of London Bridge and forced to close when landlord Network Rail took possession of them for the station’s redevelopment.

Answer: headquarters_location