A customer returning defective merchandise should be given an immediate refund if the merchandise was defective when purchased and was not on sale; if the customer is returning merchandise that is not defective or was damaged by customer negligence or customer abuse, the customer should be referred to the manager. Which one of the following judgments conforms most closely to the principle stated above? ['A customer purchased a lawn mower, which became inoperative after the customer used it only five times. Even though the lawn mower was not on sale when purchased, the customer should be referred to the manager.', 'A customer purchased a set of wrought-iron patio furniture at the regular price. The welding on two of the chairs was faulty, causing both to collapse during their first use. The customer should be given an immediate refund.', 'A customer purchased a microwave oven that stopped working after the customer accidentally dropped it. The oven was not on sale and was not damaged by abuse, so the customer should be given an immediate refund.', 'A customer purchased twelve bags of cement at the regular price, to build a walkway. The walkway was completed with only ten bags and the customer wishes to return the two remaining bags. The customer should be given an immediate refund.']