The microscope in cell studies — practice question

An electron micrograph reveals a virus of one type at a magnification of $\times 30\,000$. What is the virus's length?

• A$2.2 \times 10^3\,\text{nm}$
• B$2.2 \times 10^2\,\text{nm}$
• C$2.2 \times 10^1\,\text{nm}$
• D$2.2 \times 10^0\,\text{nm}$