A wax sample is heated. It starts to melt at $45\,^\circ\text{C}$ and has completely melted by $49\,^\circ\text{C}$. A liquid sample is heated. It starts to boil at $141\,^\circ\text{C}$ and stays at $141\,^\circ\text{C}$ during boiling. Which conclusion can be drawn from these results?
- ABoth substances are impure.
- BBoth substances are pure.
- CThe wax is not a pure substance and the liquid is a pure substance.
- DThe wax is a pure substance and the liquid is not a pure substance.