Utilize the input text as a context reference, choose the right relationship between Sergio Marchionne and Fiat 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.

Fiat Chrysler Chief Sergio Marchionne and UAW President Dennis Williams were to take questions from the media at a news conference scheduled to begin shortly in Detroit.

Answer: employer