An aircraft travels from London to Sydney in 21 hours 40 minutes. The distance covered is $17\,000\,\text{km}$. Determine the aircraft's average speed.
- A$2.2\,\text{m s}^{-1}$
- B$2.2 \times 10^7\,\mu\text{m s}^{-1}$
- C$2.2 \times 10^{11}\,\text{nm s}^{-1}$
- D$2.2 \times 10^6\,\text{mm s}^{-1}$