## Core Concept
The parachute reflex, also known as the parachute response or protective reflex, is a postural reflex that helps in maintaining posture and balance. It is particularly important in protecting the head and body from injury during a fall. This reflex involves the extension of the limbs to create a sort of 'parachute' effect, which helps in slowing down the descent and mitigating the impact.

## Why the Correct Answer is Right
The parachute reflex is most prominent and clinically significant in infants, helping them protect themselves from falls. As infants grow and develop, this reflex typically matures and then integrates, meaning it becomes less obvious as voluntary motor control and balance improve. By around 6 months of age, infants start showing a more mature response to protective reflexes, and by 9 to 10 months, these reflexes have usually matured to the point where they are less easily elicited or have integrated.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because parachute reflexes start appearing and are significant in early infancy, not disappearing immediately at birth.
- **Option B:** This option suggests 3 months, which might be too early for the disappearance of parachute reflexes as they are usually more prominent and relevant in early infancy and start to integrate as the infant grows.
- **Option D:** This option suggests 18 months, which might be too late for the typical integration of parachute reflexes as they usually mature and integrate earlier.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the parachute reflex is an important protective mechanism, particularly in infants. Its presence and subsequent integration are indicators of neurological development. Clinicians often test for this reflex as part of the neurological examination in infants to assess their neurological status.

## Correct Answer: C.