Choice "A" is correct. Under the UCC, risk of loss rules, the risk of loss passes to the buyer on tender of delivery where the seller is a non-merchant who is making the delivery.
Choices "c" and "d" are incorrect. Where the seller is a nonmerchant, the risk of loss passed to the buyer upon tender of delivery, despite the fact that the buyer stated that he would return later to pick the goods up.
Choice "b" is incorrect. Under the UCC, where the seller is a nonmerchant and a shipment contract is not involved, the risk of loss passes to the buyer on tender of delivery and not when the contract was formed.