At room temperature, substance L is a brown liquid, and its melting point is $-7\,^{\circ}\text{C}$. Which temperature corresponds to the boiling point of pure L?
- A$-77\,^{\circ}\text{C}$
- B$-7\,^{\circ}\text{C}$ to $+7\,^{\circ}\text{C}$
- C$59\,^{\circ}\text{C}$
- D$107\,^{\circ}\text{C}$ to $117\,^{\circ}\text{C}$