Take context from the input text and decide on the accurate relationship between 'Sergio Marchionne' and 'Fiat' from the options provided.
Options: headquarters location, brand, creator, employer

FRANKFURT (Reuters) - Fiat plans to keep all German Opel plants open should its takeover plans for the General Motors unit succeed but would cut staff there, Fiat Chief Executive Sergio Marchionne told a newspaper.
employer