Utilize the input text as a context reference, choose the right relationship between Mary Barra and General Motors 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.

The most improved brand is General Motors (NYSE: GM ) ("CEO Mary Barra has made it her goal to ... make sure errors of the past are not forgotten and not repeated"), followed by Target (NYSE: TGT ), travel website Trivago and GM brands Chevrolet and Buick.
employer