A

Explanation:

The answer provided in the attachment is “A” (attempted performance), but this may be incorrect. In contract law, when a promisor offers to perform their obligations and the promisee refuses to accept, it is referred to as a “tender” of performance (option C). Tender discharges the promisor from further liability for non-performance if the offer was valid. Option A (attempted performance) is not a standard legal term in this context. Option B (vicarious performance) involves performance by a third party. Option D (frustration) involves impossibility of performance. The explanation notes the likely error, but per instructions, the answer “A” is used.