**Core Concept**
The Apgar score is a method to quickly assess the health of a newborn baby immediately after birth. It evaluates five components: heart rate, respiratory effort, muscle tone, reflex response, and skin color.

**Why the Correct Answer is Right**
The Apgar score is calculated by assigning a score of 0 to 2 for each component, with 2 being the best score. In this scenario, the baby is blue (score 1 for skin color), has irregular gasping respiration (score 1 for respiratory effort), and a heart rate of 60 beats/min (score 1 for heart rate). The baby also has some flexion of extremities, indicating poor muscle tone (score 1 for muscle tone). Since the reflex response is not explicitly stated, it cannot be scored. Therefore, the total Apgar score for this newborn is 4.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided as the question only includes options B, C, and D.
**Option B:** This option is not provided as the question only includes options B, C, and D.
**Option C:** This option is not provided as the question only includes options B, C, and D.

**Clinical Pearl / High-Yield Fact**
The Apgar score is a useful tool for quickly assessing the newborn's condition and identifying those who may need immediate medical attention.

**Correct Answer: D. 4**