(b) That's right. On these facts it is unlikely that performance of the contract has been frustrated. It is important to notice that there are no known facts that indicate that the parties intended specifically to buy and sell Australian-grown wheat; or that they intended to contract on the assumption that locally grown wheat would continue to be available. A agreed to supply 'wheat', and wheat continues to be available elsewhere in the world, even if it is more difficult to get and more expensive. Compare this situation with the example on page 6.3.
A contract is not frustrated every time performance turns out to be more difficult or costly than expected. Rather it must be established that what was agreed has become absolutely impossible, or impossible within the assumptions on which the parties based their contract. On the known facts, the present case is better treated as one in which A has taken a commercial risk.