I have no idea i need points sorry
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.
Well I have personal experience with this. I had chronic pain for a long time and I couldn't go anywhere. I couldn't go to see my friends or to go outside and enjoy anything because I was in constant pain. Eventually, I had depression due to lack of joy in my life and lack of going outside. If you are stuck with physical pain and it causes you to be non-mobile, then you are going to have mental and social issues. Hope this helps :)
