1.)F, friend of D, approaches C and tells him: "I will pay you what D owes you. From now on, consider me your debtor, not D. D is to be excused. Do you agree?" C agrees. Is there expromission here?

2.)D and C entered into a contract whereby D was to give C P800,000 in cash. Later, they novated the contract by stipulating that instead of cash, D would give a particular car. Subsequently, the car was destroyed by a fortuitous event. Is D obliged to give P800,000?