Refer to the input text as context and select the correct relationship between 'Sinopec' and 'Beijing' from the available options.
Options: creator, stock exchange, location of formation, founded by

SHANGHAI Aug 21 Safety hazards have been found at almost 70 percent of firms handling dangerous chemicals inspected in Beijing since two massive blasts killed 114 people last week, including a branch of Asia's largest refiner Sinopec Corp, state media reported.
location of formation