An impure specimen of compound X has a melting point of $120\,^{\circ}\text{C}$. X is then purified, and its melting point is measured once more. Which row is the correct one?
- Acrystallisation; melting point of pure X = $115\,^{\circ}\text{C}$
- Bdistillation; melting point of pure X = $115\,^{\circ}\text{C}$
- Ccrystallisation; melting point of pure X = $125\,^{\circ}\text{C}$
- Ddistillation; melting point of pure X = $125\,^{\circ}\text{C}$