**Core Concept:** Neonatal mortality rate is a crucial metric in assessing the health outcomes of newborns. It represents the number of deaths in the neonatal period (first 28 days of life) per 1000 live births.

**Why the Correct Answer is Right:** To calculate the neonatal mortality rate, we need to determine the number of deaths and divide it by the number of live births, and then multiply by 1000. In this case, the neonatal mortality rate is calculated as follows:

Total deaths in the neonatal period = 50 (stillbirths) + 50 (deaths within 7 days) + 150 (deaths within the first 28 days) = 250

Number of live births = 4050

Neonatal mortality rate = (Total deaths / Number of live births) x 1000
Neonatal mortality rate = (250 / 4050) x 1000 = 6.14

**Why Each Wrong Option is Incorrect:**

A. This option is incorrect because it does not correctly calculate the neonatal mortality rate based on the given data.
B. This option is incorrect because it does not calculate the neonatal mortality rate accurately, as it only considers stillbirths and does not include early neonatal deaths.
C. This option is incorrect because it does not calculate the neonatal mortality rate accurately, as it only includes deaths within the first 7 days and does not consider the first 28 days.
D. This option is incorrect because it does not calculate the neonatal mortality rate accurately, as it only includes deaths within the first 7 days and does not consider the first 28 days.

**Clinical Pearls:**

1. Neonatal mortality rate is an important indicator of the quality of healthcare services in a particular region or country. A lower neonatal mortality rate indicates better healthcare conditions.
2. Understanding neonatal mortality rates can help healthcare professionals and policymakers develop targeted interventions to reduce neonatal mortality and improve neonatal health outcomes.