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.

"We continue to believe that Walmart must generate low-single-digit comp-store sales growth in its U.S. grocery business to drive sustainable positive traffic and low-single-digit consolidated comp-store sales," he said.

Answer: operator