**Core Concept**
The maxilla is a paired bone in the face that forms the upper jaw and palate. Its development and growth are influenced by various genetic and environmental factors. The maxilla achieves maximum size during specific stages of growth and development.

**Why the Correct Answer is Right**
The maxilla reaches its maximum size during puberty, around 14-15 years of age in girls and 16-17 years in boys. This is due to the increase in estrogen and testosterone levels, which stimulate the growth of the maxillary bone. The maxilla then undergoes a process called ossification, where the cartilaginous growth plates fuse, resulting in the achievement of maximum size.

**Why Each Wrong Option is Incorrect**
* **Option A:** This is incorrect because the maxilla does not achieve maximum size during infancy. The maxilla is still growing and developing during this stage.
* **Option B:** This is incorrect because the maxilla does not achieve maximum size during childhood. While the maxilla is growing rapidly during childhood, it still has a significant amount of growth potential.
* **Option D:** This is incorrect because the maxilla does not achieve maximum size after puberty. While the maxilla may undergo some additional growth after puberty, it has already reached its maximum size.

**Clinical Pearl / High-Yield Fact**
The maxilla is a dynamic bone that continues to grow and change throughout life. Understanding the growth and development of the maxilla is crucial for orthodontic and oral surgery procedures.

**Correct Answer:** C.