Christy Is Eleven Months Old

Christy is eleven months old. She has mastered the ability to run and often challenges her beleaguered parents to impromptu dashes toward whatever happens to catch her eye. Developmentally speaking, Christy is:

A) a typical infant.
B) a few months ahead of the average infant.
C) a few months behind the average infant.
D) abnormally slow in achieving large muscle coordination.