Answer:
there is no age limit for exercise, the more you do it, the more you are fit and chances of living longer
<span>The electrical stimulus in the heart begins in the APEX OF THE ATRIA at the SINOATRIAL NODE. The heart has its own electrical conduction system that enables it to work as a unit and supply oxygenated blood throughout the body. This system needs to work in a sequential manner so that the delivery of unoxygenated blood to the lungs will not backflow to other parts of the heart and the body. </span>
Answer: the answer is b
Explanation: i did some research on this before/ sorry if im wrong