Which of the following is an effective thesis statement for a cause-and-effect essay?

A- Because of the dangers of cigarette smoking, including cancer, heart disease, and even death, many smokers are on the difficult, but rewarding, path to quitting.
B- Because cigarette smoking is dangerous, I really think cigarettes should be completely outlawed.
C- Cigarettes have existed since the early 19th century.
D- My mom finally quit smoking, and this essay is about what that experience was like for her.