What are the effects of smoking on physical health?

The correct choice highlights the significant detrimental impact smoking has on physical health, specifically pointing to decreased lung function and an increased risk of disease. Smoking introduces harmful substances into the body, which can lead to chronic obstructive pulmonary disease (COPD), emphysema, and cancer, particularly lung cancer. These conditions directly impair lung capacity and function, making it more difficult for individuals to engage in physical activities and exercise effectively.

Furthermore, smoking compromises the immune system, making the body more susceptible to infections and various diseases. The long-term exposure to tobacco smoke also contributes to other serious health issues, such as cardiovascular disease, respiratory illnesses, and a host of other health complications. Consequently, the cumulative effects of smoking can significantly hinder overall health and well-being, leading to diminished performance in physical activities and a reduced quality of life.

In contrast, increasing stamina and strength or improving overall fitness levels would be false effects, as smoking negatively impacts physical capabilities. Similarly, while smoking could alter social relationships, it does not enhance them; rather, it may lead to social stigma and reduced participation in healthy social scenarios, such as physical activities common in social settings.