Take context from the input text and decide on the accurate relationship between 'grocery' and 'Walmart' from the options provided.
Options: operator, director/manager, currency, manufacturer

"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 writes.
operator