Gatsby did not leave West Egg even though Nick tells him to do so because he was waiting for Daisy to give him a call and a go-signal that both of them will run away and live a different and brand new life together. Gatsby was a hopeless romantic that was just waiting and has always been waiting and wanting for the love of his life, which was none other than, Daisy.
You probably need to study the notes that need for the test or ask for practice ones and have a teacher or a classmate help u understand why its the answer <span />