Final answer:
A family member of the consumer is generally not authorized to enroll someone in a Medicare Advantage plan without specific legal authority, such as a power of attorney.
Step-by-step explanation:
The individual who would not likely have the authority to enroll a consumer in a Medicare Advantage Plan is c. Family Member of the Consumer. Certified insurance agents, licensed insurance brokers, and Medicare-eligible individuals themselves generally have the authority or the right to enroll in a Medicare Advantage Plan; however, a family member does not inherently have this authority unless they have a legal document such as a power of attorney.