XVII. Rosario obtained a loan of P100,000.00 from Jennifer, and pledged her diamond ring. The contract signed by the parties stipulated that if Rosario is unable to redeem the ring on due date, she will execute a document in favor of Jennifer providing that the ring shall automatically be considered full payment of the loan. Is the contract valid? Explain. (3%) Will your answer to [a] be the same if the contract stipulates that upon failure of Rosario to redeem the ring on due date, Jennifer may immediately sell the ring and appropriate the entire proceeds thereof for herself as full payment of the loan? Reasons. (3%)