Which of the following factors can be changed to improve health?

Improving health often involves addressing behaviors and lifestyle choices that significantly impact well-being. Smoking is a modifiable risk factor; quitting smoking can lead to numerous health benefits, including reduced risk of chronic diseases such as heart disease, lung diseases, and various cancers. It is important to recognize that behaviors like smoking are under individual control and can be changed through intervention, support, and personal motivation.

In contrast, other factors such as genetics, chronic stress, and age represent more stable aspects of an individual's health landscape. While chronic stress can be managed to some degree through lifestyle changes and coping mechanisms, it is not as readily modifiable as smoking, which can be definitively quit or avoided. Genetics and age are inherent to an individual and cannot be changed, although their effects may be mitigated through healthy lifestyle choices. Thus, focusing on smoking as a factor that can be changed underscores the importance of personal agency in health improvement efforts.