One of the Challenges with Doing a Cross-Sectional Study Is

Multiple Choice

One of the challenges with doing a cross-sectional study is that

A) you must have groups that cover the entire age range from infancy through adolescence.
B) you must be certain that the different age groups you use are as similar to each other as you possibly can make them.
C) it will be hard to get the statistical tools that you need to adequately analyze your data.
D) your findings may no longer be relevant by the time your study is completed.