Question

keenan is a sprinter on his schools track team. during a race, his breathing rate increases until it is much higher than his resting breathing rate. his breathing rate remains elevated until the race is over. once the race is finished, keenans breathing rate gradually returns to normal. which graph could show keenans breathing rate during and after a race?

Explanation:

Step1: Analyze the breathing rate pattern

Keenan's breathing rate increases until the race, stays elevated during the race, then decreases after the race. So the graph should have three phases: increase, constant, decrease.

Step2: Compare the two graphs

• The first graph: Increases, then stays constant (during race), then decreases (after race).
• The second graph: Increases, then decreases continuously (no constant phase during race).

So the first graph matches the pattern.

Answer:

The first graph (with the horizontal segment during the race)