**Core Concept**
The size of organs and structures at birth is a critical aspect of pediatric anatomy. The human body undergoes significant growth and development after birth, with various organs and structures maturing at different rates. Understanding the size of organs at birth is essential for pediatric diagnosis and management.

**Why the Correct Answer is Right**
The size of organs at birth is a crucial factor in pediatric medicine. The kidneys, liver, and brain are relatively small at birth compared to adult size. However, the stomach, small intestine, and pancreas are approximately the size of an adult at birth. This is because these organs need to accommodate the rapid growth and development that occurs in the first few years of life.

**Why Each Wrong Option is Incorrect**
* **Option A:** This is not a valid option, as the question does not provide information about the size of the lungs, heart, or spleen at birth.
* **Option B:** This is not a valid option, as the question does not provide information about the size of the adrenal glands, thyroid gland, or parathyroid glands at birth.
* **Option C:** This is not a valid option, as the question does not provide information about the size of the eyes, ears, or limbs at birth.

**Clinical Pearl / High-Yield Fact**
One important clinical correlation is that the stomach and small intestine are capable of accommodating a large volume of milk at birth, allowing for rapid growth and development in the first few months of life.

**Correct Answer:** D.