William will be presenting his mid-year paper in front of the class. his classmates are talking as they come into class and take their seats. when william's teacher says something to him, he tries to focus on what she is saying while tuning out the other voices. analyzing this example using a gestalt perceptual principle, the noisy environment is and his teacher's voice is

Two technicians are discussing oil changes. technician a says that waste oil and old filters need to be disposed of according to the law. technician b says that old filters can be returned to the parts department for a core value. which technician is correct?           a. technician a only   b. both technicians a and b   c. technician b only   d. neither technician a nor b