Substance L has a melting point of $-7\,^{\circ}\text{C}$ and appears as a brown liquid at room temperature. What is 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 $117\,^{\circ}\text{C}$