Final answer:
The parachute response is the one primitive reflex not expected to disappear by about 6 months of age, unlike the other reflexes which typically fade as the nervous system matures. Therefore, the correct option is D.
Step-by-step explanation:
Among the primitive reflexes listed, the parachute response is not generally expected to disappear by about 6 months of age. The other reflexes mentioned, such as the rooting reflex, Moro reflex, palmar grasp, and tonic neck reflex, are typically gone by around 4 to 6 months of life as the infant's nervous system matures. However, the parachute response develops later and persists throughout life as it is related to the development of protective responses.