POS stands for Point-of-Service, a hybrid health plan that combines features of HMOs and PPOs. You can choose to use the plan like an HMO (in-network, lower cost) or PPO (out-of-network, higher cost) at the 'point of service' when you need care. Options B, C, and D are incorrect - it's 'Point-of-Service', not 'Product', 'Safety', or 'Procedure'.