Answer: Austyn's heart rate is up quite a bit compared to Shanice which means either he was working out harder or since he's a male he has a larger heart which need more blood through the body. The heart rate is affected by how hard you work out? The size and possibly the condition of your heart?
Explanation:
The answer that seems like would best fit this graph would be "(4)Years"
It is important because they are used to produce sugar during the dark reaction
