Answer:
Excused for frustration of purpose,commercial impracticability or impossibility of performance
Step-by-step explanation:
Frustration of purpose implies a situation where the expected performance under the contract differs from actual performance due to unforeseen condition which hampers the intended performance.
Commercial impracticability means that from an economic perspective, the promise under the contract could not be fulfilled because it is economically impossible to do so,for instance ABC industries cannot begin to recruit new employees in order to fulfill CBA's order as it might be impossible to find employees that are good fit and even cost implication might be unbearable