Which One of the Following Describes a Longitudinal Study

Multiple Choice

Which one of the following describes a longitudinal study?

A) The same children are tested at 1,3,5,and 10 years of age.
B) Different children are tested at 1,3,5,and 10 years of age.
C) Some children are tested at 1,3,and 5 years of age while other children are tested at 3,5,and 10 years of age.
D) The same children are tested at 1,3,and 5,and another group of children are tested at 2,4,and 6.