Alla, Bob, Cindy, Dave, and Emilia ate birthday cake last night. After dessert, there was one slice left, so they decided to leave it for Freddy, but someone ate it! Freddy knows that these 5 people are each telling one truth and one lie. Alla says, It wasn't Emilia. It was Bob. Bob says, "It wasn't Cindy. It wasn't Emilia." Cindy says, "It was Emilia. It wasn't Alla." Dave says, "It was Cindy. It was Bob." Emilia says, "It was Dave. It wasn't Alla." Who ate the last slice of cake? (A) Alla (B) Bob (C) Cindy (D) Dave (E) Emilia