Which of the Following Is True

Which of the following is true?

A) Past consideration is sufficient legal consideration to enforce an agreement.
B) Contracts based on a party's past consideration are unenforceable unless some new consideration is given to support the contract.
C) Contracts based on a party's past consideration are known as illusory contracts.
D) Contracts based on a party's past consideration are generally enforceable on the grounds of moral obligation.
E) Contracts based on a party's past consideration are known as quasi-contracts.