Three weeks after the 2004 Indian Ocean tsunami, prevalence of PTSD among children in Sri Lanka ...

Three weeks after the 2004 Indian Ocean tsunami, prevalence of PTSD among children in Sri Lanka ranged between 14 and 39 and could be predicted by variables such as family loss and severity of exposure. This finding indicates that ____.
 
  a. children in Sri Lanka were below the norm of expected levels of PTSD
  b. children are particularly susceptible to stress and PTSD
  c. tsunamis are far more of a source of PTSD for children than being injured in an automobile accident
  d. tsunamis are far less of a source of PTSD for children than being injured in an automobile accident