Consideration for a Promise Will Be Sufficient to Establish a Binding

Consideration for a promise will be sufficient to establish a binding agreement where:

A) The price paid by the promisee is a vague promise to do something or refrain from doing something.
B) The price paid for the promise was paid before the promise was made.
C) The price paid by the promisee was the fulfilment of a prior legal obligation, that is, the performance of something the promisee was already legally obliged to do.
D) The price paid has some legal value even if it is not a fair or adequate price.