Utilize the input text as a context reference, choose the right relationship between Visa Europe and Visa Inc 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.

Under a long-standing agreement between them, Visa Europe has a put option which would oblige Visa Inc to acquire it at a price calculated by a detailed formula.

Answer: parent_organization