Final answer:
The California Department of Managed Health Care (DMHC) regulates California HMO plans.
Step-by-step explanation:
The California Department of Managed Health Care (DMHC) regulates HMO plans in California. The DMHC ensures that HMOs comply with state laws and regulations to protect consumers and promote access to quality healthcare. They oversee the licensing, financial stability, and operations of HMO plans, and also handle consumer complaints and enforcement activities.