In which, if any, of the following independent situations has Trent made a gift? a. Trent established an irrevocable trust, income payable to himself for life and, upon his death, remainder to his children. b. Trent dies owning a U.S. savings bond with ownership listed as: "Trent, payable to Sue on Trent's death." Sue redeems the bond. c. Trent sends $25,000 to Alice's oral surgeon in payment of her dental implants. Alice is Trent's sister and does not qualify as his dependent. d. Trent pays Eva $800,000 in a property settlement of her marital rights. One month later Trent and Eva are divorced. e. None of the above.