Final answer:
The health risk associated with ground-level ozone is respiratory issues.
Step-by-step explanation:
The health risk associated with ground-level ozone is respiratory issues (Option 2). Ozone is highly reactive and can oxidize and destroy lung tissue. Short-term exposures to elevated ozone levels can cause respiratory irritations such as coughing, wheezing, and soreness. Prolonged exposure can lead to permanent lung function reduction and an increased risk of developing asthma. Therefore, both options a) cancer and b) respiratory issues are incorrect, and the correct answer is option 2) respiratory issues.