What frequency of asthma symptoms will a certain percentage of Americans experience?

The correct choice indicates that a significant percentage of Americans will experience asthma symptoms at some point in their life. This understanding is grounded in the fact that asthma is one of the most common chronic respiratory conditions in the United States, affecting millions of people. The possibility of experiencing symptoms throughout one’s lifetime suggests that asthma is not only a concern for those who are currently diagnosed but also for others who may develop the condition later due to environmental factors, allergens, or genetic predispositions.

This choice reflects the broader epidemiological data showing that asthma can manifest in various ways and at different times in a person's life, such as during childhood or even later in adulthood. Therefore, it is crucial for personal trainers and health professionals to be aware of this when designing exercise programs or advising clients who may have asthma or are at risk for asthma, ensuring safety and efficiency.