Explain and answer briefly the following question:

Subject: Obligation and Contacts

4. Are the following obligations valid, why, and if they are valid, when is the obligation demandable in each case? a) If the debtor promises to pay as soon as he has the means to pay b) if the debtor promises to pay when he likes c) If the debtor promises to pay when he becomes a lawyer. d) If the debtor promises to pay if his son, who is sick with cancer, does not die within one year. 5. In two separate documents signed by him, Juan Valentino "obligated" himself each to Maria and Perla, thus - "To Maria, my true love, I obligate myself to give you my house and lot located at Raois, Vigan City when lfeel like it." and "To Perla, my true sweetheart, | obligate myself to pay you Php 5,000, I owe when I feel like it." Months passed but Juan never bothered to make good his promises. Maria and Perla came to consult you on whether or not they could recover on the basis of the foregoing settings. What will be your legal advice be