An empty flask has a mass of $34\,\text{g}$. A volume of $20\,\text{cm}^3$ of liquid is poured into the flask. The combined mass of the flask and the liquid is $50\,\text{g}$. Calculate the density of the liquid.
- A$0.80\,\text{g cm}^{-3}$
- B$1.25\,\text{g cm}^{-3}$
- C$2.50\,\text{g cm}^{-3}$
- D$4.20\,\text{g cm}^{-3}$