**Core Concept**
Criminal negligence refers to a gross deviation from the standard of care expected of a medical professional, resulting in harm or death to a patient. This concept is crucial in medical jurisprudence, as it holds healthcare providers accountable for their actions.

**Why the Correct Answer is Right**
Section 304 A of the Indian Penal Code (IPC) deals with causing death by negligence. The maximum punishment for criminal negligence under this section is two years imprisonment and/or a fine. This provision is specifically designed to address situations where a medical professional's gross negligence results in a patient's death. The IPC defines gross negligence as a marked departure from the standard of care expected of a medical professional, indicating a reckless disregard for a patient's safety.

**Why Each Wrong Option is Incorrect**
**Option A:** Two years imprisonment is incorrect because it is the maximum punishment for voluntarily causing hurt (Section 323 IPC), not criminal negligence (Section 304 A IPC).
**Option B:** Five years imprisonment is incorrect because it is the maximum punishment for causing grievous hurt by negligence (Section 338 IPC), not criminal negligence (Section 304 A IPC).
**Option C:** Life imprisonment is incorrect because it is the maximum punishment for culpable homicide not amounting to murder (Section 304 A IPC), not criminal negligence.

**Clinical Pearl / High-Yield Fact**
When dealing with cases of patient harm or death, it is essential to differentiate between negligence, gross negligence, and culpable homicide. This distinction is critical in determining the appropriate course of action and the potential consequences for the healthcare provider involved.

**Correct Answer: D. Two years imprisonment and/or a fine.**