Final answer:
When Martha is injured at work, her group policy will be considered primary over Medicare Part A.
Step-by-step explanation:
When Martha is injured in an accident at work, her group policy will be considered primary over her Medicare Part A. This is because group insurance is typically the primary payer when an individual has both group insurance and Medicare coverage. Group policies, which are often provided by employers, are meant to be the primary source of coverage, and Medicare serves as secondary insurance, filling in the gaps that the group policy may not cover.