Utilize the input text as a context reference, choose the right relationship between Wallis and London from the options. Options: 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.

(Additional reporting by Karolin Schaps in London and Keith Wallis in Singapore; Editing by Marguerita Choy and Tom Brown)

Answer: headquarters_location