A. Developing a thesis statement
Explanation:
Smoking inflames and irritates the lungs. Even 1 or 2 cigarets causes irritation and coughing. Smoking also can destroy your lung tissue, this decreases the number of airspaces and blood vessels in the lungs resulting in less oxygen to be given to critical parts of your body.
The Answer is A. Because B does not make sense when you say it out loud.