【单选题】Under FOB, the seller may accept the buyer's entrustment to book shipping space on behalf of the buyer at the buyer's expense. However, there is the risk that the seller may not be able to book shipping space before the stipulated date of shipment, then _____.
A. The seller is not liable for the risks; the buyer is liable for the risks.
B. The buyer is liable for the risks; the seller is liable for the risks.
C. Buyers and sellers jointly assume responsibility and risk
D. Neither parties assume responsibility and risk, and the contract terminates.