A.I. Explanation:

Option 1: "Reducing the risk of chronic diseases and improving heart health."

Explanation: The text states that regular walking can help reduce the risk of chronic diseases such as heart disease, stroke, and diabetes, which directly supports this option. Additionally, it mentions that walking improves cardiovascular health, aligning with the idea of improving heart health.

Option 2: "Boosting mental health and reducing stress levels."

Explanation: The passage highlights that walking can boost mood and mental health, which supports the first part of this option. While it does not explicitly mention reducing stress levels, the improvement in mood can imply a reduction in stress, making this option relevant.

Option 3: "Walking can only be done outdoors and in good weather."

Explanation: This option is incorrect because the text does not limit walking to outdoor settings or good weather. It states that walking can be done anywhere and at any time, indicating flexibility in location and conditions.

Option 4: "Walking is not a safe form of exercise."

Explanation: This option contradicts the text, which does not mention any safety concerns regarding walking. Instead, it presents walking as a simple and low-impact exercise, suggesting that it is indeed a safe form of exercise.

Option 5: "Walking doesn't burn as many calories as other forms of exercise."

Explanation: The text does not provide a comparison of calorie burning between walking and other forms of exercise. It emphasizes the health benefits of walking without making claims about its calorie-burning efficiency relative to other exercises.