What is the relationship between Inmarsat 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.

5,855.00p +2.92% Smiths Group (Other OTC: SMGKF - news ) (SMIN) 1,129.00p +2.54% FTSE 100 - Fallers Mondi (MNDI) 1,409.00p -4.67% Inmarsat (LSE: ISAT.L - news ) (ISAT) 1,001.00p -1.96% London Stock Exchange Group (LSE) 2,425.00p -1.86% Aviva (Amsterdam: AW8.AS - news ) (AV.)

Answer: headquarters_location