Final answer:
An advance directive, also known as a living will, is a written legal document that details specific interventions a person wants regarding their medical care. The statement 'I plan to write that I don't want them to keep me on a breathing machine' indicates patient understanding of advance directives.
Step-by-step explanation:
An advance directive, also known as a living will, is a written legal document that details specific interventions a person wants regarding their medical care. It is used to ensure that an individual's wishes are known and followed if they become unable to communicate their desires.
Out of the given options, the third statement, 'I plan to write that I don't want them to keep me on a breathing machine,' indicates patient understanding of advance directives. This statement shows that the patient intends to document their preference regarding the use of a breathing machine in case of a medical emergency or life-threatening situation.
The fourth statement, 'I will get my regular doctor to approve my plan before I hand it in at the hospital,' reflects an additional step the patient is taking to ensure that their advance directive is valid and in accordance with their regular doctor's approval. However, this step is not directly related to the understanding of the advance directive concept.