Which of the following examples involve a categorical variable? CHECK ALL THAT APPLY

A. A cost-effective analysis of mammography based on whether breast cancer was prevented or not among patients at a hospital.

B. A professor looking at the percentage grade distribution for the first midterm.

C. The film industry compares the age distributions of people who prefer going to movie theatres against people who prefer using Netflix.

D. The Canadian Food Inspection Agency (CFIA) determines if a batch of chocolates is safe to eat based on whether each chocolate has less than 0.01 g of mold.

E. None of the above