e. Why Sonny is a one-of-a-kind NS-5 robot compare to other NS-5 models

Sonny is a special robot created by Lanning. Sonny resembles more a human that a robot in his manners and thoughts, though his look is fully robot like. Sonny is albe to dream dreams, and analyze people’s gestures. This helps him to provide assistance Spooner and Susan in deactivating VIKI. In the end it becomes evident that it was Sonny who killed Lanning, and that the doctor commanded him to do this.