Which of the Following Is Not a Disadvantage of an HMO

Which of the following is not a disadvantage of an HMO plan versus a PPO plan?

A) The HMO plan may be less expensive.
B) The HMO plan is more restrictive on which doctors the patient is able to use.
C) The HMO plan often requires a referral in order to see a specialist.
D) The HMO plan is generally more expensive for the same level of coverage.