题目选项分析

Phytonutrients, found in fresh fruits and vegetables, have beneficial effects on the human cardiovascular system. Because heart disease is a major health concern, American doctors should encourage all people, especially those with heart disease, to eat a diet high in fresh fruits and vegetables.

Which of the following, if true, provides the most support for the argument above?

【选项】smoking cigarettes is a much more serious health risk than the lack of fresh fruits and vegetables in one's diet