What Is True of Cross-Sectional Studies? Select All That Apply

What is true of cross-sectional studies? Select all that apply.

A) Cross-sectional data is considered new data (i.e., collected after the disease or injury) .
B) The challenge of cross-sectional data is not knowing whether the relationship existed before the injury or disease or as a consequence of the disease.
C) With cross-sectional data, it could be possible there is no relationship between the data and the disease.
D) Cross-sectional data must have existed before the disease or injury (i.e., historical data) .