**Core Concept**
Central macular fixation is a critical aspect of visual development, where the fovea becomes the primary point of focus for visual acuity. This process involves the maturation of the central retina and the establishment of a clear, high-acuity visual field. The development of central macular fixation is essential for tasks requiring precise visual attention.

**Why the Correct Answer is Right**
Central macular fixation typically develops around 4-6 months of age, as the fovea matures and the retina gains the ability to process high-acuity visual information. During this period, the infant's visual system undergoes significant changes, including the refinement of visual pathways and the establishment of binocular vision. The development of central macular fixation is closely tied to the maturation of the optic nerve and the visual cortex.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as central macular fixation is not typically present at birth.
**Option B:** This option is incorrect as central macular fixation is not fully developed until around 4-6 months of age.
**Option C:** This option is incorrect as central macular fixation is not established until after the initial visual development milestones are met.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the development of central macular fixation is a critical milestone in visual development, and its presence or absence can have significant implications for infant assessment and diagnosis of visual impairments.

**Correct Answer: B. 4-6 months of age**