Which expenses are covered by Medicare Part D?

Detailed Answer in Step-by-Step Solution:

Medicare Part D (C) specifically covers prescription drug costs for enrollees.

Medical expenses (A) are under Part B, hospital costs (B) under Part A, and dental (D) is generally not covered by Medicare unless supplemental.

The Virginia study guide states that Medicare Part D, introduced in 2006, provides prescription drug coverage through private plans, distinct from Parts A and B. Reference: Virginia Life, Annuities, and Health Insurance study guide, section on "Medicare."