What did a study by Strayer and Johnston (2001) regarding the effects of attention on driving conclude? A. Attention is not affected as long as one is using a hands-free phone. B. Driving and talking with friends in the car increases the chance of an accident. C. Driving and listening to the radio increases the chance of missing traffic signals. D. Driving and talking on any type of cell phone increases the chance of missing traffic signals. Please select the best answer from the choices provided A B C D.