Utilize the input text as a context reference, choose the right relationship between Airbnb and San Francisco 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.

Twilio, a San Francisco company that makes software development tools, uses Airbnb to put up some new hires for as long as a month while they relocate from a different city.

Answer: headquarters_location