Context: When I came back up , I heard enthusiastic WEE - OO - WEE - OO coming from his room . I popped my head in there and he made the noise at me and grinned . I asked " Firetruck ? "
Question: Why might he make that sound ?
Option 0: I said " firetrucks " so he made the noise .
Option 1: He was playing make - believe with himself .
Option 2: I like firetrucks so he made the noise .
Option 3: He felt enthusiastic that I was in his room .
Answer: 1