Ray has the diagnosis of acute stress disorder; Bob has been diagnosed as suffering from posttraumatic stress disorder. What is a major difference in their conditions?

a. Bob has had symptoms for longer than Ray has had symptoms.
b. Ray's symptoms are the result of a social stressor, not a natural stressor.
c. Bob's symptoms involve a greater level of autonomic nervous system activation.
d. Ray is likely to have more trouble sleeping than Bob, who is more likely to have appetite difficulties

Answer: a.