Who is most likely eligible to enroll in a Part D prescription drug plan?

The correct choice includes a 65-year-old who is eligible for Part A and has just enrolled in Part B, as eligibility for a Medicare Part D prescription drug plan is generally linked to enrollment in Medicare Part A or Part B. Individuals who are 65 years old or older and are enrolled in Medicare have the right to sign up for a Part D plan, as this is one of the core criteria for eligibility.

In this context, enrolling in Part B is important, as it signifies that the individual has completed the necessary steps to receive Medicare coverage. Individuals under 65 with disabilities, while also potentially eligible for Part D, are not the focus here since the specified answer pertains specifically to those aged 65 and over who are newly enrolled in Part B. Similarly, a 50-year-old who is a new beneficiary would not yet qualify for Medicare, as the standard age for eligibility is 65 unless they meet certain disability criteria. Lastly, a senior who has never enrolled in Medicare may have lost their opportunity to enroll in a Part D plan, as enrollment windows are limited and usually require initial signup during their Medicare enrollment period.