What Is the Impact of the Decision in MWB Business

What is the impact of the decision in MWB Business Exchange Centres Ltd v Rock Advertising (2016) on the doctrine of promissory estoppel?

A) It reinstated the traditional understanding of the requirements of reliance and inequitability by holding that an agreement to accept part-payment of a debt, without more, would not make it inequitable for the promisor to resile from his promise.
B) It was held that promissory estoppel could create a new cause of action.
C) It held that no estoppel arises in cases where a statement is made 'without prejudice'.
D) All of the above.