**Core Concept**
Informed consent is a critical aspect of medical ethics, involving a patient's voluntary and knowledgeable agreement to undergo a medical procedure or treatment. It is based on the principles of autonomy, beneficence, non-maleficence, and justice.

**Why the Correct Answer is Right**
Informed consent requires that patients be fully informed about the risks, benefits, and alternatives of a proposed treatment or procedure. This includes explaining the diagnosis, the treatment options, the potential outcomes, and any potential complications. Patients must also be given the opportunity to ask questions and seek additional information before making a decision. Informed consent is typically documented in writing, with the patient signing a consent form.

**Why Each Wrong Option is Incorrect**
**Option A:** Informed consent is not required for emergency medical procedures. However, even in emergency situations, healthcare providers must still make a reasonable effort to inform patients about their treatment and obtain their consent whenever possible.

**Option B:** Informed consent is not required for minors. However, minors do have the right to provide consent for certain medical treatments, such as reproductive health services, and healthcare providers must respect their autonomy.

**Option C:** Informed consent is not required for patients who are incapacitated. However, healthcare providers must still make a reasonable effort to obtain consent from a surrogate decision-maker or to document the patient's wishes in advance of their incapacitation.

**Option D:** Informed consent is not required for patients who are unconscious. However, healthcare providers must still make a reasonable effort to obtain consent from a surrogate decision-maker or to document the patient's wishes in advance of their unconsciousness.

**Clinical Pearl / High-Yield Fact**
The key elements of informed consent include disclosure, comprehension, capacity, voluntariness, and documentation. Healthcare providers must ensure that patients understand the information they are being given and that they are able to make an informed decision.

**Correct Answer:** D. Informed consent is not required for patients who are unconscious.