Utilize the input text as a context reference, choose the right relationship between Citigroup and Sanford Weill 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.

Former Citigroup Chairman and CEO Sanford Weill and his wife Joan have given more than $600 million to Weill Cornell Medical College and Cornell University over the years.

Answer: founded_by