Virginia Code § 38.2-4303 defines the HMO model, where the primary care physician (PCP, option A) acts as the gatekeeper, delivering preventive (e.g., vaccines) and routine care (e.g., checkups), and coordinating referrals. Option B (medical director) oversees HMO operations, not direct care. Option C (routine care physician) isn’t a standard term; the PCP fills this role. Option D (provider association) might imply a network, but care comes from the individual PCP, not a collective. The study guide likely explains the PCP’s central role with examples—e.g., a member seeing their PCP for a flu shot—highlighting HMO cost-control via this structure, making A the correct provider.