Leonardo Is a Member of a Twelve-Step Program

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.