A student was interested in the cigarette smoking habits of college students and collected data from an unbiased random sample of students. The data is summarized in the following table: 

Males Surveyed 50

Females Surveyed 75 

Males Who Smoke 20 

Females Who Smoke 25 

Males Who Do Not Smoke 30 

Females Who Do Not Smoke 50 

Why is the table NOT a frequency distribution? 

A. The number of males does not equal the sum of males that smoke and do not smoke. 

B. The classes are not mutually exclusive. 

C. There are too many classes. 

D. Class limits cannot be computed.