Which of the Following Best Describes the Concept of Promissory

Which of the following best describes the concept of promissory estoppel?

A) It is one of the required aspects of consideration.
B) It is a doctrine that stops certain promises from being enforced.
C) It is a doctrine that allows a remedy in some cases where a promise is not supported by agreement or consideration.
D) It is the concept that prevents persons from making unenforceable gift promises.
E) It is the requirement that the consideration exchanged in a contract be approximately equal.