Read the passage carefully. Which of the following statements about the argument are true? Cigarette smoke is unhealthy even for people who don’t have the nicotine habit themselves. Secondhand smoke can cause asthmatics (哮喘病患者) and sufferers of sinusitis (鼻窦炎) serious problems. Doctors regularly advise heart patients to avoid confined smoky areas because coronary attacks might be triggered by the lack of clean air. Moreover, having the smell of smoke in one’s hair and clothes is a real nuisance. Even if a person is without any health problems, exhaled smoke doubles the amount of carbon monoxide in the air, a condition that may cause lung problems in the future.
A、This is a unified paragraph.
B、The first sentence is the thesis statement.
C、It is the reasoning by cause and effect.
D、It is the reasoning by generalization.