Choice "B" is correct. In an F.O.B. place of shipment contract, risk of loss passes when the goods are placed in the hands of a carrier at the seller's loading dock.
Choice "c" is incorrect. Risk of loss would pass on identification only if the parties specifically so provided.
Choice "a" is incorrect. In an F.O.B. place of shipment contract, it is not sufficient just to get the goods to the loading dock; risk does not pass until the goods are placed in the hands of a carrier there.
Choice "d" is incorrect. In an F.O.B. place of shipment contract, risk of loss passes when the goods are placed in the hands of a carrier at the seller's loading dock.