Meltzoff and Moore Have Examined Infants' Ability to Imitate Facial

Meltzoff and Moore have examined infants' ability to imitate facial expression of a variety of sorts. They found that even newborns can imitate mouth opening and tongue protrusion. Other researchers have attempted to replicate Meltzoff and Moore's findings. The best summary of our knowledge to date is:

A) For the first six months, infants are not able to imitate movements for which there is perceptible feedback (e.g., a finger wiggle) . They can imitate behaviours for which there is no perceptible feedback.
B) Some researchers have not been able to replicate Meltzoff and Moore's findings.
C) During the first six months, we do not expect babies to imitate mouth movements, because babies tend to focus on hair rather than facial features.
D) By six months of age, babies reliably imitate movements that both do and don't provide perceptible feedback.