Utilize the input text as a context reference, choose the right relationship between British Airways 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.

British Airways owner IAG led a small group of rising stocks yesterday while the rest of the London market struggled to get airborne in the face of more ill winds from China.

Answer: location_of_formation