If a Child Achieves a Particular Developmental Milestone Early,such as Taking

If a child achieves a particular developmental milestone early,such as taking her first steps when she's only 4 months old,her parents should

A) understand that their child is very special,and hire a coach to develop her physical skills.
B) have a neuropsychologist test her for brain abnormalities.
C) hire an experienced nanny to work one-on-one with her until she's back on a normal developmental track.
D) not worry or get too excited because this is most likely just normal variation.