Walter owes Christine $100. Walter does not have the money and does not think he will anytime soon. After discussing the matter, Christine agrees to take $50 as full repayment. The parties sign a written agreement and Walter pays Christine $50. Under the common law, can Christine sue Walter to collect the remaining $50?

Maybe, but only if Walter was about to enter bankruptcy

No, because Walter completely performed his obligations under the contract

Yes, because Walter provided no consideration for the new agreement

Yes, because Christine provided no consideration for the new agreement