Which one best describes the factors that effect the severity of the health risks caused by smoking?
A. how many times one has tried to quit, how dependent upon nicotine one is, and the length of time that one has been smoking
B. the length of time that one has been smoking, how deeply one inhales, and the strength level of nicotine and other chemical content
C. how long the smoker has lived in cold weather, how many times he or she has tried to quit, and how deeply the smoker inhales
D. how old the smoker is currently, how deeply one inhales, and the strength level of nicotine and other chemical content