A student makes a drawing of a mitochondrion. This diagram is shown at a magnification of $\times 20000$. Its length on the page is 5 cm. What is the mitochondrion's actual size?
- A$0.00025\,\mu\text{m}$
- B$0.0025\,\mu\text{m}$
- C$0.025\,\mu\text{m}$
- D$2.5\,\mu\text{m}$