A sports medal has a total surface area of $150\,\text{cm}^2$. It was coated uniformly with silver by electrolysis. Its mass rose by $0.216\,\text{g}$. How many silver atoms were deposited on each $\text{cm}^2$ of the medal's surface?
- A$8.0 \times 10^{18}$
- B$1.8 \times 10^{19}$
- C$8.7 \times 10^{20}$
- D$1.2 \times 10^{21}$