A metal block with a rectangular shape has a length of $20\,\text{cm}$. Its cross-sectional area is $25\,\text{cm}^2$. The block has a mass of $4000\,\text{g}$. What is the density of the metal?
- A$0.13\,\text{g cm}^{-3}$
- B$0.32\,\text{g cm}^{-3}$
- C$8.0\,\text{g cm}^{-3}$
- D$2000\,\text{g cm}^{-3}$