**Core Concept**
The question tests the understanding of normal physiological findings in newborns, focusing on cardiovascular and respiratory adaptations after birth. **Newborn physiology** is characterized by significant changes in circulation and oxygenation.

**Why the Correct Answer is Right**
**Central Cyanosis** is a sign of decreased oxygenation of the blood and is not a normal finding in newborns, indicating a potential issue with the respiratory or cardiovascular system. In contrast, a **systolic murmur** can be a normal finding due to the closing of the ductus arteriosus, a **pulse rate of 100/min** is within the normal range for newborns, and **peripheral cyanosis** can be seen in healthy newborns due to immaturity of the circulatory system.

**Why Each Wrong Option is Incorrect**
**Option A:** A systolic murmur can be a normal finding in newborns.
**Option B:** A pulse rate of 100/min is within the normal range for newborns.
**Option C:** Peripheral cyanosis can be seen in healthy newborns.

**Clinical Pearl / High-Yield Fact**
It's crucial to differentiate between peripheral and central cyanosis, as central cyanosis is always pathological and requires immediate attention.

**Correct Answer:** D. Central Cyanosis