A lent money to B in the amount of P3M and executed a mortgage over his house and lot to secure the payment of the obligation with a condition that if he fails to pay, A shall became the owner of the property. Is the stipulation valid?

• A. Yes, because the contract is the law between the parties;
• B. Yes, because of the doctrine of mutuality of contracts
• C. No, because it is a case of pactum commissorium;
• D. Yes, because of the liberty of contracts.