Leonardo is a member of a twelve-step program. He attributes his recovery to the program's social ...

Leonardo is a member of a twelve-step program. He attributes his
  recovery to the program's social support and nutritional counseling.
  Why might these reasons reflect a biological basis for his success so
  far?
 
  A. There is no biological basis. Twelve-step programs work based
  on spirituality and personal willpower alone.
  B. Twelve-step programs work because brain chemistry is adapted
  through mental affirmations, due to the type of mind-body
  connection in addicts.
  C. Twelve-step programs facilitate relearning of adaptive social
  interactions and may alter brain chemistry in an adaptive
  direction.
  D. Twelve-step programs facilitate a new type of learning in the
  limbic system that cannot be substituted by medication-based
  changes in brain chemistry.