Answer:
The correct answer is - increased heart rate
Step-by-step explanation:
When an individual exercise his cells of muscles requires additional oxygen to produce energy to work hard or intense workout. In such a case, the body's heart pumping the blood faster to supply oxygen and blood to the whole body, especially the organs and muscles that are being strained during the activity therefore it will beat at a faster rate and therefore the increased rate of the heart is the main body response.