His whistle slowed questioningly as he looked around . The kitchen , which was situated by the door , was empty , as was the living room . I 'll just leave the book where Kai can find it , he decided , and stepped into the kitchen , closing the door firmly behind him . He was about to leave it on the counter , but then he spotted the freshly baked tarts . Immediately his mouth began to water .

Question: Why might the narrator be leaving a book ?
Answer: He thinks Kai will enjoy itHe wrote it himselfHe wants Kai to pay him for itHe does not want it any more