What is the MAIN difference between self-help groups and inpatient or outpatient treatment for alcohol abuse?

a.Inpatient or outpatient treatment for alcohol abuse is less effective than self-help groups.

b.Health Insurance is required for participation in inpatient or outpatient treatment.

c.Self-help groups are run by recovering alcoholics for the benefit of other recovering
alcoholics.

d.Participating in inpatient or outpatient treatment is involuntary; self-help groups are voluntary