The Data in the Accompanying Table Came from a Study

The data in the accompanying table came from a study where adults reported their dietary intake and researchers measured their BMIs to measure obesity rates. The results seem to suggest that low-carbohydrate diets are associated with lower body weights. However, this is a case of correlation and not causation. Therefore, what else could possibly explain these results?

A) The people who ate the most carbohydrates exercised more than the other groups.
B) The people who ate the least carbohydrates exercised more than the other groups.
C) The people who ate the most carbohydrates took more vitamins than the other groups.
D) The people who ate the least carbohydrates took more vitamins than the other groups.