Do you have answers to the problems on page 22 of this document? Or at least where I can find the answers? Thanks

1. O owns a pearl ring. While visiting her daughter A, O leaves the ring on the bathroom sink. After O leaves, A discovers the ring. When A telephones O to tell her of the discovery, O tells A to keep the ring as a gift. Has O made a gift to A? If so, can O change her mind the next day and require A to return the ring?