The body temperature inside some animals, including humans, stays unchanged even if the temperature outside varies. The graph illustrates the effect of a change in external temperature on the oxygen used by one of these animals. Which conclusion can be drawn from this graph?
- AThe animal stops respiring when the external temperature is greater than $28\,^{\circ}\text{C}$.
- BThe animal’s respiration rate increases as the external temperature decreases from $28\,^{\circ}\text{C}$.
- CThe internal temperature of the animal decreases as the external temperature increases.
- DThe animal’s respiration rate increases as the external temperature increases.