The passage explicitly states, "Studies have shown that exercise releases endorphins, chemicals in the brain that act as natural painkillers and mood elevators." It further explains that these endorphins contribute to improved mental well-being by acting as mood elevators and reducing symptoms of anxiety and depression. Option 1 directly reflects this fact, making it the correct choice.
Option (b): The passage contradicts this option by stating, "Contrary to common misconceptions, it doesn't require intense workouts; even moderate activities like walking or yoga can contribute to improved mental well-being," making this option false.
Option (c): This is incorrect, as the passage emphasizes the opposite: "Engaging in regular physical activity is not only beneficial for physical well-being but also has a profound impact on mental health."
Option (d): The passage refutes this by noting that moderate activities like walking or yoga can reduce anxiety and depression, as seen in the excerpt: "even moderate activities like walking or yoga can contribute to improved mental well-being."
Hence, the correct answer is option (a).