## **Core Concept**
The question tests knowledge of human development, specifically the growth patterns of various organs and structures in relation to birth. At birth, most organs are proportionally sized for the newborn's needs, but some continue to grow significantly after birth.

## **Why the Correct Answer is Right**
The correct answer, , refers to the eyes. The eyes are known to be approximately 70% of their adult size at birth and continue to grow until the child is about 7-8 years old, reaching full adult size. This is a crucial aspect of pediatric ophthalmology, as the size and shape of the eye can influence vision development and the potential for refractive errors.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not specify an organ or structure that is not of adult size at birth. Without the specific content of Option A, we can infer that it likely refers to an organ or structure that is relatively well-developed at birth.
- **Option B:** Similarly, this option is incorrect for the same reason as Option A; it likely represents an organ or structure that is of adult size or nearly so at birth.
- **Option D:** This option is also incorrect as it presumably refers to another organ or structure that is well-developed or of adult size at birth.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that the eyes are not fully grown at birth, which is why children's vision can change significantly as they grow. This underlines the importance of regular eye exams in pediatric care to detect any vision problems early.

## **Correct Answer: C. Eyes**