Refer to the input text as context and select the correct relationship between 'Mary Barra' and 'General Motors' from the available options.
Options: stock exchange, operator, employer, location of formation

DETROIT (Reuters) - General Motors Co (GM.N) Chief Executive Mary Barra said the automaker plans new efforts to capitalize on the connectivity built into its cars, expanding car sharing services, offering more autonomous driving features and enabling services through smartphone apps.
employer