Not 100% sure but B sounds the most likely from what I've read...
B. cancer
Explanation:
Smoking causes cancers of the lung, esophagus, larynx, mouth, throat, kidney, bladder, liver, pancreas, stomach, cervix, colon, and rectum, as well as acute myeloid leukemia
The DNA requires an adequate supply of nutrients, growth factor stimulation, and space which is provided after the death of the previous cells. When there is enough cytoplasm for two cells, the cells divide after the supply of energy from the nutrients.