Which is the strongest evidence to support the claim?

Which is the strongest evidence to support the claim?
1. Researchers have shown that stress can be a factor in the development of heart disease, depression, and obesity.
2. A study by the American Psychological Association cited that money and work were two of the most common sources of stress in the United States.
3. On a community health forum, one of the top contributors wrote, "I'm sure that my high blood pressure is directly linked to my level of stress."