The graph illustrates how a person's body temperature changes during a 60-hour period. Which statement about the graph is correct?
- AThe temperature of the person is always lower at 18:00 than at 06:00.
- BThe range shown by the data is $1.0\,^{\circ}\text{C}$.
- CThe temperature of the person after 9 hours from the start is $36.8\,^{\circ}\text{C}$.
- DOver this period, the mean temperature of the person at 18:00 is $36.8\,^{\circ}\text{C}$.