The answer is:
C. Many Americans are addicted to smoking and consume more than three packs of cigarettes a day.
A. The American Cancer Society has stated that smoking three packs of cigarettes a day reduces life expectancy.
B. Though Americans live in a well-developed country, Americans are reducing their life expectancy on a daily basis.
Syllogism is a logical argument based on deductive reasoning, in which a conclusion is supported by two premises. The minor premise consists of the subject of the conclusion; in this case, "many Americans are addicted to smoking." The major premise contains the predicate of the conclusion, such as "smoking three packs of cigarettes a day reduces life expectancy. " As a result, the conclusion is a deductive combination of the two propositions.