Shoppers observe a Walmart mobile food testing lab at one of its outlets in Shenzhen. The world’s largest retailer announced yesterday that it is offering a money-back guarantee on the fruits and vegetables it sells at all of its stores in China as well as the O2O platform it launched in Shenzhen earlier this month. The money-back guarantee allows customers to return fresh produce to the store for a full refund within 14 days after they bought it. All the returned goods will be destroyed, it said.SD News