Question $4(1$ point$)$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 $$50.$Disregarding promissory estoppel, can Christine sue Walter to collect the remaining$$50?$a$)$ Yes, because Christine's new agreement is considered a gratuitous promise and therefore not binding b$)$ Yes, because Walter provided consideration for the new agreement O c$)$ No$,$ because any new contract takes priority over old contractsd$)$ No$,$ because Walter completely performed his obligations under the new contract