**Core Concept**
The age of consent for medical examination and treatment is a crucial legal concept that varies by jurisdiction. In the context of medical practice, it refers to the minimum age at which an individual is considered capable of giving informed consent for medical treatment. This concept is essential in pediatric and adolescent medicine, where minors may require medical care without their explicit consent.

**Why the Correct Answer is Right**
The correct answer is based on the legal principle that minors below a certain age are not considered capable of giving informed consent for medical treatment. In many jurisdictions, including India, the age of consent for medical treatment is 18 years, as per the Indian Penal Code (IPC) and the Medical Council of India (MCI) regulations. This means that individuals below 18 years of age require the consent of a parent, guardian, or legal representative for medical treatment.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately reflect the age of consent for medical treatment in most jurisdictions. The age of consent for medical treatment is generally higher than 12 years.

**Option B:** This option is incorrect because it does not accurately reflect the age of consent for medical treatment in most jurisdictions. The age of consent for medical treatment is generally higher than 16 years.

**Option C:** This option is incorrect because it does not accurately reflect the age of consent for medical treatment in most jurisdictions. The age of consent for medical treatment is generally higher than 14 years.

**Clinical Pearl / High-Yield Fact**
It is essential for medical professionals to be aware of the age of consent for medical treatment in their jurisdiction to ensure that they obtain the necessary consent before providing medical care to minors.

**Correct Answer: D. 18 years.**