Several months ago, Fiat Chrysler CEO Sergio Marchionne sent Barra an email saying he wanted the two companies to merge, a notion Barra has consistently said she and the company's board of directors are not interested in.
Refer to the input text as context and select the correct relationship between 'Sergio Marchionne' and 'Fiat' from the available options.
Options: parent organization, employer, operator, platform