The legal enforcement of an otherwise unenforceable contract due to a party's detrimental reliance on the contract is known as ________.

A) promissory estoppel
B) substantial estoppel
C) the promissory rule
D) the reliance rule
E) promissory reliance

Promissory estoppel is a legal principle that allows for the enforcement of a contract that is otherwise unenforceable, based on one party's detrimental reliance on the promises of the other party. It prevents the promisor from arguing that an underlying promise should not be legally upheld or enforced.