Utilize the input text as a context reference, choose the right relationship between grocery and Walmart 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.

"Meanwhile, as competitors like Kroger, Publix, H-E-B, Jewel-Osco and others have invested in evolving customer lifestyle trends – by broadening organic and fresh offerings – and in improving customer service, the gap between both comp-store sales growth and customer satisfaction at Walmart U.S. grocery and supermarket competitors continues to widen," Hood wrote in a note to clients Monday.

Answer: operator