The difference between an HMO and a PPO is that:A) Patients who are members of a PPO have less opportunity to choose their own caregivers than do members of an HMO. B) HMOs are affected by managed care, whereas PPOs are not.C) HMOs are usually managed by physicians, whereas PPOs are usually managed by health care administrators and business graduates.D) Physicians and other caregivers work directly for an HMO or they may be apart of a network of HMOs, whereas they maintain more autonomy as affiliates of a PPO.