As a Demonstration in Your Abnormal Psychology Class, Your Instructor

As a demonstration in your abnormal psychology class, your instructor shows a videotape of children taken at their first birthday parties. Half of the children were subsequently diagnosed with autistic disorder. The instructor asks the class to select the children they believe received this diagnosis. Which of the following indicators would be the best predictor of the diagnosis?

A) imitating the movements of others
B) infrequently looking at the face of another
C) spending most of the time with eyes closed
D) moving hands around in a seemingly random fashion