Answer:
A. Wilson may use the doctrine of promissory estoppel to show that he had materially relied on the oral promise and will suffer serious losses if the promise is not enforced.
Explanation:
The doctrine of promissory estoppel is of relevance to this case. While there was no written contract, in law, an oral contract is also applicable and so an individual can be sued on the basis of an oral contract. The last option is out of question because it is difficult to prove that it was an unintentional tort because that requires proof of loss which is difficult to calculate.