A student was told to use the scale bar shown in order to calculate the magnification of a cell in a photomicrograph. The scale bar indicates $2\ \mu\text{m}$. Which method could the student use to calculate the magnification of the cell?
- Adivide the diameter of the cell by the length of the scale bar, with both measured in the same units of length
- Bmeasure the diameter of the cell in millimetres, multiply by 2000 and divide by the length of the scale bar measured in millimetres
- Cmeasure the length of the scale bar in millimetres, convert to micrometres and divide by $2$
- Dmeasure the length of the scale bar in millimetres, convert to micrometres and multiply by $2$