Final answer:
Smoking is the pre-existing condition that can significantly impact morbidity and mortality, leading to diseases like lung cancer and heart disease. A healthy lifestyle with good nutrition and exercise lowers risk factors for noninfectious diseases like diabetes and cardiovascular disorders.
Step-by-step explanation:
Pre-existing conditions that affect morbidity and mortality include lifestyle factors and behaviors such as unhealthy diet, lack of exercise, and tobacco use. In particular, smoking is a significant risk factor that can lead to chronic respiratory diseases like lung cancer and cardiovascular diseases. Therefore, the correct answer to the question which of the following pre-existing conditions affect morbidity and mortality is C) Smoking.
Maintaining a healthy lifestyle through good nutrition and regular physical activity can reduce the risks of many noninfectious diseases, like type 2 diabetes, various cancers, and heart diseases that are prevalent in many developed countries. To reduce one's risk for these conditions, it's vital to avoid exposure to carcinogens, engage in regular exercise, maintain a balanced diet, and ensure adequate sleep.