Take context from the input text and decide on the accurate relationship between 'grocery' and 'Walmart' from the options provided.
Options: operator, subsidiary, platform, member of

Reddit Email Print Reprint NEW YORK ( TheStreet ) --  Walmart ( WMT - Get Report ) stock is increasing by 0.42% to $63.93 in mid-morning trading on Tuesday, after the company announced it will expand a service that allows customers to pick up their online grocery orders from store parking lots.
operator