a, because exercise doesn't just aid the prevention of certain diseases, it helps prevent many diseases. i would've chosen d if it wasn't so specific but a is the correct answer.
Since there are no options listed to choose from, my best guess would be watches, since a lot of apple watch products are now sold with built in heart monitors.
Answer:
turn off the radiator immediately and move the box away from the heat
Explanation:
Answer: Aerobic Heart Rate Zone
This is the zone to aim for when training for endurance. It spurs your body to improve your circulatory system by building new blood vessels and increases your heart and lung capacity. Aiming for 20 to 60 minutes in this zone is believed to give the best fitness training benefits.
