Leaders of the market for these remedies, like Beijing Tongrentang Co Ltd, have products with snakeskin, dried toad, centipede, scorpion and dandelion to treat swelling, and others with oyster, ginseng and black-bone chicken for menstrual pains.
In the context of the input sentence, determine the relationship between 'Tongrentang' and 'Beijing'.
Options: parent organization, stock exchange, developer, headquarters location