Utilize the input text as a context reference, choose the right relationship between OnStar and General Motors 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.

On Thursday, a researcher warned that hackers could exploit a security flaw in a mobile app for General Motors Co's (GM.N) OnStar vehicle communications system.

Answer: parent_organization