Take context from the input text and decide on the accurate relationship between 'Lyft' and 'SAN FRANCISCO' from the options provided.
Options: subsidiary, distribution format, headquarters location, owned by

SAN FRANCISCO (Reuters) - The Massachusetts attorney general's office is examining how Uber and Lyft ensure equal access for people with disabilities, a spokeswoman for the attorney general told Reuters, adding to numerous other business issues facing the two companies.
headquarters location