The answer is letter B.
In the event that a person suddenly stops after an intense workout without cooling down, aneurysm and heart attack are possible to happen. During an intense workout everything in the body is performing extra. This extra performance causes the heart to pump at a faster rate, the blood vessels to dilate, the muscles to contract at a speedy rate, among others. Cooling down is an essential part of any fitness program as this slowly brings the body back into homeostasis. It is often overlooked by many but the risks of possible accidents to happen are high when this is not performed in exercise.
Diseases like the one destroying humanity right now impact human populations by taking away a considerable amount of people away. This can be arguably effective in tackling overpopulation in places like India and China, whilst negatively affecting places like the USA, which could lead to higher immigration and more problems
I’m pretty sure it is kidney problems