Final answer:
Medicare, the Joint Commission, and the National Committee for Quality Assurance have all established documentation standards in healthcare, making 'all of the above' the correct answer.
Step-by-step explanation:
The entities that have established documentation standards for healthcare include Medicare, the Joint Commission, and the National Committee for Quality Assurance (NCQA). Therefore, the correct answer to which entities have established documentation standards is d) all of the above. These organizations are responsible for ensuring the quality and accountability of healthcare services, and one of their tools to achieve this is through setting documentation standards that healthcare providers must follow.