The diagram depicts an organelle shown at a magnification of $\times 20\,000$. What is the greatest length of the organelle?
- A$3 \times 10^{-1}\,\mu\text{m}$
- B$3 \times 10^{0}\,\mu\text{m}$
- C$3 \times 10^{1}\,\mu\text{m}$
- D$3 \times 10^{2}\,\mu\text{m}$