Which act guarantees patients the right to make decisions about their medical care?

The Patient Self-Determination Act is the correct answer because it specifically focuses on ensuring that patients have the right to make informed decisions about their medical care. This legislation mandates that healthcare providers inform patients about their rights to make these decisions and to have advance directives, such as living wills or healthcare proxies, that express their preferences regarding medical treatment in the event they become unable to communicate those wishes.

This act emphasizes the importance of patient autonomy and empowerment in healthcare. By requiring healthcare institutions to recognize and facilitate patients' rights to determine the course of their treatment, the law supports informed consent and the individual's right to choose or refuse medical interventions.

The other acts mentioned relate to aspects of healthcare but do not primarily focus on patient decision-making rights in the same way. For instance, the Health Insurance Portability and Accountability Act deals mainly with protecting patient privacy and health information, while the Patient Protection and Affordable Care Act focuses on expanding healthcare access and affordability. The Medicare Access and CHIP Reauthorization Act primarily addresses issues related to Medicare reimbursement and children's health programs, rather than individual patient rights in decision-making.